PHGDH and neoplasm: Importantly, we observed an inverse correlation between circulating HDL-c and transcript levels of Phgdh and five enzymes of the mevalonate pathway (Mvd, Sqle, Cyp51, Hsd17b7, and Dhcr24) in tumor bed, suggestive of an inhibitory role for apoA-I/HDL in cancer cell metabolism (Figure 6).