Although the remarkable efficacy of SFXN4 knockout in inhibiting tumor growth in vivo precluded assessment of the combined effects of drug treatments and SFXN4 inhibition in vivo, immunohistochemical staining of tumors revealed that nuclear RAD51 was lower in SFXN4 knockout tumors than in controls (Fig. 6B). The gene discussed is SFXN4; the disease is neoplasm.