Here, we have examined the effect of three chemotherapy drugs that are commonly administered to childhood cancer patients; CYP (through administration of its active metabolite PM), CIS and DOX, using a prepubertal mouse in vitro system that has been shown to maintain normal morphological appearance of the seminiferous tubules and support the survival and proliferation of the germ and somatic cell compartments, with the Control cultured testis tissue similar to that in vivo15. This evidence concerns the gene PPIG and in situ carcinoma.