CTLA4 and liver cancer: By focusing on liver cancer, researchers have discovered a negative correlation between p53 and survival, as well as identified potential immunotherapeutic targets such as WNT signaling, MDM4, MET, VEGFA, MCL1, IDH1, TERT, and immune checkpoint proteins CTLA-4, PD-1, and PD-L1 (Cancer Genome Atlas Research Network 2017).