In addition, the male mice that were double mutants for Dnd1+/Δ; Nanos3+/Cre showed a drastic increase in the ratio to 84.3%, indicating a synergistic effect of combining heterozygous mutations for Dnd1 and Nanos3. Based on these data, we conclude that both Nanos2 and Nanos3 interact with Dnd1 in the regulation of testicular teratoma incidence. This evidence concerns the gene DND1 and testicular teratoma.