CD4 and obesity disorder: Some DEGs within this pathway are involved in major histocompatibility complex class II (MHC-II)-related antigen presentation, which aligns with previous findings that hypertrophic adipocytes can function as antigen-presenting cells (APCs), directly activating CD4+ T cells via the enhanced MHC-II pathway in obesity.23 However, another set of genes, whose role in obesity has received little attention, is associated with MHC-I-related antigen presentation.