NEU1 and breast cancer: Co-expressed gene transcripts in this module, associated with the luminal vs TNBC set, were C6orf211, CCND1, CERS6, ESR1, and THSD4. Enrichment and pathway analysis of the full set of genes related to BC subtypes revealed that four of these CERS6, ELOVL6, NEU1, and SERINC3 were involved in sphingolipid metabolism, whereas C6orf211 (ARMT1), CCND1, and ESR1 were annotated in the breast cancer KEGG pathway.