PSAT1 and breast cancer: We also found significant correlation between the transcript levels of two out of three SBP enzymes—PHGDH and PSAT1—and the immune infiltration‐associated gene expression pattern (immune score, ESTIMATE) (Yoshihara et al, 2013) (Fig 5E–G) in the METABRIC breast cancer transcriptome dataset (Curtis et al, 2012), indicating that inflammation is also a key regulator of the SBP in addition to known oncogenes (Yang & Vousden, 2016).