found that obesity or metabolic syndrome-related M1 macrophages up-regulated PD-L1 expression in TNBC by partially secreting IL-6 in a JAK/STAT-dependent pathway, which in turn affected immunotherapy targeting the PD-L1/PD-1 axis in vitro (144). Here, SOAT1 is linked to obesity due to melanocortin 4 receptor deficiency.