PSAT1 overexpression impairs the prognosis of cancer by promoting cancer cell proliferation, metastasis, as well as chemoresistance discovered that NRF2 regulates the expression of the important serine synthesis enzymes PHGDH, PSAT1, and SHMT2 through the activation of ATF4 to promote glutathione and nucleotide formation [115]. Here, ATF4 is linked to cancer.