CD4 and hepatocellular carcinoma: After adjustment based on tumor purity using TIMER database, RAB42 expression was positively correlated with infiltrating levels of B cells (r = 0.49, p = 3.73e−22), CD8+ T cells (r = 0.421, p = 3.89e−16), CD4+ T cells (r = 0.437, p = 1.78e−17), macrophages (r = 0.59, p = 2.16e−33), neutrophils (r = 0.478, p = 3.86e−21), and DCs (r = 0.59, p = 2.54e−33) in HCC but negatively correlated with tumor purity (r = −0.25, p = 2.57e−06) (Figure 7A).