diff --git a/VariantValidator/modules/format_converters.py b/VariantValidator/modules/format_converters.py
index 354379e6..9e69b5b5 100644
--- a/VariantValidator/modules/format_converters.py
+++ b/VariantValidator/modules/format_converters.py
@@ -280,7 +280,10 @@ def vcf2hgvs_stage1(variant, batch_list):
     if vcf_data[3] == '.':
         vcf_data[3] = ''
 
-    if re.search(r'[^CGAT]', vcf_data[2]) or re.search(r'[^CGAT,]', vcf_data[3]):
+    if (
+            not set(vcf_data[2]) <= {"A", "C", "G", "T"}
+            or not set(vcf_data[3]) <= {"A", "C", "G", "T", ","}
+    ):
         logger.debug("Completed VCF-HVGS step 1 for %s", variant.quibble)
         return False
 
diff --git a/VariantValidator/modules/hgvs_utils.py b/VariantValidator/modules/hgvs_utils.py
index 9bd293c2..c5e5d25d 100644
--- a/VariantValidator/modules/hgvs_utils.py
+++ b/VariantValidator/modules/hgvs_utils.py
@@ -625,12 +625,10 @@ def pvcf_to_hgvs(query, selected_assembly, normalization_direction, reverse_norm
     try:
         input_list = query.split(':')
         position_and_edit = input_list[1]
-        if not re.match(r'N[CGWT]_', query) and not re.match(r'LRG_\d+$', query):
-            chr_num = str(input_list[0])
-            chr_num = chr_num.upper()
-            chr_num = chr_num.strip()
-            if re.match(r'CHR', chr_num):
-                chr_num = chr_num.replace('CHR', '')
+        if not query.startswith(("NC_", "NG_", "NW_", "NT_")) and not re.fullmatch(r"LRG_\d+", query):
+            chr_num = input_list[0].strip().upper()
+            if chr_num.startswith("CHR"):
+                chr_num = chr_num[3:]
             # Use selected assembly
             accession = seq_data.get_accession(chr_num, selected_assembly)
             if accession is None:
diff --git a/VariantValidator/modules/use_checking.py b/VariantValidator/modules/use_checking.py
index dc63c779..70fa3bde 100644
--- a/VariantValidator/modules/use_checking.py
+++ b/VariantValidator/modules/use_checking.py
@@ -189,13 +189,13 @@ def pre_parsing_global_common_mistakes(my_variant):
                 logger.info(error)
                 return True
 
+
             elif (
-                    (
-                        re.search(r'\(ENST\d+\.\d+\):', quibble)
-                        or re.search(r'\(N[MRCG]_\d+\.\d+\):', quibble)
-                        or re.search(r'\(LRG_\d+t\d+\):', quibble)
+                    re.search(
+                        r"\((?:ENST\d+\.\d+|N[MRCG]_\d+\.\d+|LRG_\d+t\d+)\):",
+                        quibble,
                     )
-                    and not quibble.startswith('NC_')
+                    and not quibble.startswith("NC_")
             ):
                 reference_region, variation = quibble.split(':', 1)
                 reference = reference_region.split('(', 1)[1].replace(')', '')
diff --git a/VariantValidator/modules/vvMixinCore.py b/VariantValidator/modules/vvMixinCore.py
index 3ebcab7d..bac60736 100644
--- a/VariantValidator/modules/vvMixinCore.py
+++ b/VariantValidator/modules/vvMixinCore.py
@@ -379,11 +379,10 @@ def validate(self,
                         elif selected_assembly == 'hg38':
                             primary_assembly = 'GRCh38'
                         # Ensure genome build is correctly formatted
-                        elif re.search('GRC', selected_assembly, re.IGNORECASE):
-                            selected_assembly = selected_assembly.replace('g', 'G')
-                            selected_assembly = selected_assembly.replace('r', 'R')
-                            selected_assembly = selected_assembly.replace('c', 'C')
-                            selected_assembly = selected_assembly.replace('H', 'h')
+                        elif selected_assembly.upper().startswith("GRC"):
+                            selected_assembly = (
+                                    selected_assembly[:3].upper() + selected_assembly[3:].lower()
+                            )
                             primary_assembly = selected_assembly
                         # Catch invalid genome build
                         if primary_assembly in self.genome_builds or primary_assembly == 'hg38':
@@ -415,16 +414,19 @@ def validate(self,
                         if match:
                             result = match.group()
 
-                            # Check if Ens submitted as RefSeq set and vice versa
-                            if "ENST" in result and transcript_set == "refseq":
+                            # Check if Ensembl transcript submitted as RefSeq set and vice versa
+                            if result.startswith("ENST") and transcript_set == "refseq":
                                 my_variant.warnings.append(
-                                    "InvalidFieldError: The transcript " + result + " is not in the RefSeq "
-                                    "data set. Please select Ensembl")
+                                    f"InvalidFieldError: The transcript {result} is not in the RefSeq "
+                                    "data set. Please select Ensembl"
+                                )
                                 continue
-                            elif ("NM_" in result or "NR_" in result) and transcript_set == "ensembl":
+
+                            elif result.startswith(("NM_", "NR_")) and transcript_set == "ensembl":
                                 my_variant.warnings.append(
-                                    "InvalidFieldError: The transcript " + result + " is not in the Ensembl "
-                                    "data set. Please select RefSeq")
+                                    f"InvalidFieldError: The transcript {result} is not in the Ensembl "
+                                    "data set. Please select RefSeq"
+                                )
                                 continue
                             try:
                                 to_code_or_not_to_code = self.hdp.get_tx_identity_info(result)
diff --git a/VariantValidator/modules/vvMixinInit.py b/VariantValidator/modules/vvMixinInit.py
index 9df94ecd..36802662 100644
--- a/VariantValidator/modules/vvMixinInit.py
+++ b/VariantValidator/modules/vvMixinInit.py
@@ -2,7 +2,6 @@
 
 import logging
 import os
-import re
 from configparser import ConfigParser
 
 import vvhgvs
@@ -606,14 +605,11 @@ def _remake_unc(
                         hgvs_protein.posedit.edit.alt
                     )
 
-                    if re.search(r"\*[A-Z]+", protein_alt):
-                        protein_alt = (
-                            protein_alt.split("*")[0] + "*"
-                        )
-
-                        hgvs_protein.posedit.edit.alt = (
-                            protein_alt
-                        )
+                    if "*" in protein_alt:
+                        head, _, tail = protein_alt.partition("*")
+                        if tail[:1].isupper():
+                            protein_alt = head + "*"
+                            hgvs_protein.posedit.edit.alt = protein_alt
 
                 except Exception:
                     pass