The ERK1/2 pathway regulates testosterone synthesis by coordinately regulating the expression of steroidogenic genes in Leydig cells

► Deletion of Mek1/2 decreases expression of androgenic genes in Leydig cells. ► Deletion of Mek1/2 increases expression of androgen metabolism genes in Leydig cells. ► Deletion of Mek1/2 decreases androgen synthesis in Leydig cells.