TP53 and cancer: In addition, vitamin D supplementation reduced the risk of relapse in the subgroup of patients who had sufficient infiltration of immune cells into the tumor microenvironment in our previous research.23 We therefore hypothesized that vitamin D supplements may reduce the risk of relapse or death by enhancing anticancer immunoreaction, indicated by the presence of antibodies against mutated p53 proteins as cancer-specific antigens that are distinct from normal p53.