PDCD1 and infection: In undernutrition 65% + infection group, PD-1 (P = 0.0364), PD-L1 (P = 0.0481) and Bax (P = 0.0394) were conversely upregulated, and ICOS (P = 0.0274), TLR2 (P = 0.0097) and TLR4 (P = 0.0361) were also upregulated.