The ssGSEA scores of most immune cells in high NAD+ biosynthetic subtypes were higher than those in low NAD+ biosynthetic subtypes, which indicated that the immune microenvironment in BC with high biosynthesis score tended to be “hot.” Our results also showed that HER2-enriched and Basal subtypes had higher NAD+ biosynthesis score, which were consistent with higher TILs infiltration in the two molecular subtypes (38). The gene discussed is ERBB2; the disease is breast cancer.