Genetic background also clearly influenced tumor gender specificity in Dmd – mice (male preference in BALB/c, female in C3H) and tumor site predilection in Dysf −/− mice (∼60% abdominal wall tumors in C57BL/10 x B6C3Fe compared to ∼20% in C57BL/10). The gene discussed is DMD; the disease is neoplasm.