CD4+ T cells that express NK cell markers and cytotoxic enzymes have also been reported in human bladder cancer (Oh et al. 2020), NSCLC (Guo et al. 2018), melanoma (Kitano et al. 2013), and hepatocellular carcinoma (Zheng et al. 2017), and these CD4+ NK-like T cells have been shown to have tumor killing activity (Oh et al. 2020). This evidence concerns the gene CD4 and neoplasm.