For example, Map3k4 is known to be required for mouse testis determination, while mutations in the closely related gene, MAP3K1, are associated with 46,XY CGD in humans.30,120Map3k1 is not, however, required for mouse testis determination.132 Details of the mechanistic role of MAPK signaling in testis development should solve the problem of apparent discrepancies such as this and reveal whether the bigger picture is one of conserved or divergent mechanisms. The gene discussed is MAP3K1; the disease is chronic granulomatous disease.