CTLA4 regulates T cells differently than the PD-1/PD-L1 axis and the combination of ipilimumab with anti-PD1 or anti-PD-L1 antibodies demonstrated synergic effects in suppressing the development of various tumors, such as melanoma and NSCLC [43,44]. Here, PDCD1 is linked to non-small cell lung carcinoma.