ALK and neoplasm: Patients with gene alterations such as EGFR mutations and ALK translocations are considered less likely to respond to PD-1/PD-L1 inhibitors because of the relatively low frequency of PD-L1 expression and lack of effector T-cell trafficking into the tumor microenvironment [31]; this characteristic is probably attributable to the relatively low mutation burden, resulting in reduced generation of neopeptides that could be recognized by T-cells.