PRDM1 and in situ carcinoma: In contrast, orthotopic injection of TCam-2 into the testis leads to CIS /seminoma-like growth within the seminiferous tubules, indicated by a CIS /seminoma-like morphology (uniformly growing big round cells with a big nucleus, weakly eosinophilic) and expression of typical markers like SOX17, BLIMP1, VASA, TFAP2C and cKIT.