Specifically, we aimed at the verification of the synthetic lethality concept of HMOX1 and FH in three different HLRCC cell lines using not only genetic but also pharmacological inhibition of HMOX1. We were especially interested in checking the effectiveness of SLV-11999 inhibitor, described by us recently as the anti-cancer compound in pancreatic and prostate cancer cell lines [23]. The gene discussed is FH; the disease is cancer.