Although this report demonstrated for the first time the participation of PD-1+ and PD-L1+ cells in the skin of patients with CBM, the same markers of cell exhaustion have been described as factors associated with disease progression in infections caused by viruses [64,66], bacteria [67,68,69,70,71,72], protozoans [73,74], and helminths [75,76,77]. Here, PDCD1 is linked to infection.