Large, integrative single-cell studies focused on breast cancer have extended and refined this taxonomy: Zhang et al. constructed a breast-cancer TAM atlas that delineates seven transcriptional TAM subtypes (e.g. TUBA1B+, C1QC+, VCAN+, IL1B+, SLC40A1+, APOC1+, CXCL11+) whose relative abundance varies by molecular subtype and stage, implying functional specialization and dynamic remodeling within the TME [51]. The gene discussed is APOC1; the disease is breast cancer.