TP53 and diffuse large B-cell lymphoma: On the other hand, inactivating mutations of TP53, which can be detected in approximately 20% of DLBCL patients [89,114,115,116], have been shown to increase PD-L1 expression in various tumour types [101,117,118] and might result in defective p53-regulated miRNA responses that normally control PD-L1 levels [119,120].