CD4 and cancer: More recently, studies have shown the contribution of CD4+ CTL in cancer cell eradication in human using RNAseq in multiple solid cancers (non-small-cell lung cancer [120], colorectal cancer [43], hepatocellular carcinoma [44], bladder cancer [45], osteosarcoma, breast cancer [46,47], head and neck cancer [48] and melanoma [12]).