PDCD1 and coinfection: Finally, microbial translocation (sCD14), exhaustion (PD-1/TIGIT)- and senescence (TREC)-associated markers along with immune activation profile (IgG1/IgG3 and CD38/HLA-DR) deserve to be better investigated as underlying determinants of relapse or chronicity of VL in patients with HIV co-infection, in addition to being evaluated using algorithms to validate them as prognostic biomarkers (Figure 1, Table 1).