FH and hereditary leiomyomatosis and renal cell cancer: The HLRCC model has been used for identifying selective drug targets through a synthetic lethality (SL) approach and led to the identification of enzymes along the heme biosynthesis pathway as potential SL-pair targets of FH. Indeed, experimental validation of such a target, HMOX, was shown to selectively kill FH-deficient cells while sparing the normal ones (Fig3).