CD274 and cancer: On the other hand, other studies have shown that many patients who respond to PD-1, PD-L1 immunotherapy develop acquired resistance to immunotherapies over time [273], prompting researchers to consider a variety of other strategies and combination therapies to improve the efficacy of cancer immunotherapies in larger numbers of patients [274,275], as well as to investigate standard variables that influence immunotherapy efficacy, such as T-cell production, effector function mediation, and the establishment of stable immunological memory [276,277,278].