RAD50 and spermatogenic failure: Knockdown of RAD50 leads to a decrease in the expression level of two proteins in spermatocytes (GC-2spd), and downregulation of RAD50 inhibits the proliferation of GC-2spd cells and promotes apoptosis, which is consistent with the simultaneous decrease in RAD50 in the testes of spermatogenic failure patients [30].