Abstract: The present invention relates to a genetically modified human stem cell, in which said human stem cell comprises an exogenous nucleic acid comprising a region coding for a fusion protein comprising a mutant human cytochrome P450 2B6 (CYP2B6*) protein of SEQ ID No. 1 or a variant or fragment thereof and an NADPH-cytochrome P450 reductase protein of SEQ ID No. 2 or a variant or fragment thereof, functionally bound to a promoter, said exogenous nucleic acid having been integrated into one of the genomic safe harbors of said human stem cell. The invention also relates to the use of said cell for the treatment of cancer and/or cancer recurrences and/or associated metastases, particularly the solid tumours, and in particular the hepatocellular carcinomas and/or associated metastases.