CTLA4 and cancer: Immune checkpoint inhibition with blockade of the PD-1/PD-1 ligand 1, CTLA-4/cytotoxic T lymphocyte-associated antigen 4, LAG3/lymphocyte-activation gene 3, and TIM3/T cell immunoglobulin pathways may improve the quality of the cellular immune response to MTB epitopes, as seen in cancer immunotherapy [4,5,45–47].