NANOS2 and testicular teratoma: In the case of crossing with Nanos2 mutant mice (Figs 5A and S4A), the ratio of affected male mice slightly increased from 2.9% in wild-type male mice to 8.8% in Nanos2+/LacZ male mice and 11.8% in Nanos2LacZ/LacZ male mice, indicating that Nanos2 is one of the genes responsible for testicular teratomas, as previously reported [24].