However, to our surprise, there was no significant difference between the KNL1-Ctrl mice and the KNL1-60 μg mice (Figure 5C,D), which confirmed that apoptosis was not the main factor inducing reproductive degeneration phenotype of oligospermia and azoospermia, as many previously reported [38,39,40]. This evidence concerns the gene KNL1 and Azoospermia.