TP53 and neoplasm: On the other hand, several studies indicate a pathogenic role for SIRT1 in solid tumors and leukemias [45] and with the chemoresistant phenotype, but other studies suggest tumor-suppressive functions [46,47], implying that the role of SIRT1 in cancer may be context dependent, varying by the tumor type, specific oncogenes present, and mutation status of p53 or other target proteins [45].