Acquired resistance means the cases in which patients have response to ICB therapy initially, but have tumor progression after a duration of therapy.575 Investigations to find out possible predictors of response to immunotherapy blockade have revealed that PD-L1 expression, tumor mutational burden,576,577 tumor intrinsic oncogenes, such as IFN-γ, p53, and Wnt signaling,578–581 signatures of T cell dysfunction and antigen presentation expression,582–586 gut microbiota and its derived metabolites587–589 are all significantly associated with clinical benefit. This evidence concerns the gene TP53 and neoplasm.