SLC40A1 and breast cancer: TUBA1B+ TAMs, C1QC+ TAMs and VCAN+ TAMs were more prevalent in HER2+ breast cancer, whereas IL1B+ TAMs, SLC40A1+ TAMs and APOC1+ TAMs were more dominant in ER+ breast cancer, which illustrates the heterogeneity of TAM subtypes in various molecular subtypes of breast cancer.