TSSK4 and testicular embryonal carcinoma: In addition, when we knocked down QRICH2 in NT2 cells (human testicular embryonic carcinoma cell) which have been identified to express QRICH2, AKAP3, CABYR, ODF2, and TSSK4, and the decreased protein amount of AKAP3, CABYR, ODF2, and TSSK4 was observed in these knocked-down cells compared to the control cells (Supplementary Fig. 5d), Therefore, the decreased levels of the proteins which we focus on are caused by the reduced expression of QRICH2 directly but not the lack of sperm tail structures.