GRM8 and breast cancer: The Sorcs3+ group was divided into two subclusters by elevated expression of Grm8 or Cacna1e. Previously identified BC-enriched immunohistological markers NefH and Ret52,53 showed enrichment within the Sorcs3+/Grm8+ subcluster but they were not among the top differentially expressed transcripts (Fig. 4b, c).