PDCD1 and Obesity: In addition, several innate immune receptors involved in antigen-presentation (HLA-DR), phagocytosis and antibody-dependent response (CD16), effector functions (CD11c), chemotaxis (CD182), suppressive activity (PD-L1 and PD-1), inflammation (TREM-1) and hemoglobin clearance (CD163) were strongly associated with clinical markers of severity in patients with obesity.