APOE and melanoma: In contrast, M2 macrophages, known for their immunosuppressive role, exhibited expression of anti-inflammatory molecules MSR1, CD163, MRC1, C1Q, SELENOP, and APOE. TAMs were characterized by their expression of TREM2, ITGAM, CCL20, and IL1B. While we employ the M1/M2 nomenclature to denote inflammatory and anti-inflammatory macrophage states, these clusters align with in vivo macrophage subtypes described in melanoma and other cancers25.