Some drugs enhance tumor immunity by up regulating PD-L1 in tumor cells, such as Panobinostat(LBH589) (Atadja, 2009; Woods et al., 2015), Chidamide (CS055/HBI-8000) (Ning et al., 2012; Yan et al., 2020; Que et al., 2021), Trichostatin-A (TSA) (Li et al., 2021) and ACY738 (Regna et al., 2016; Maharaj et al., 2020). The gene discussed is CD274; the disease is neoplasm.