FHL5 and Azoospermia: The expression of CREMτ and its coactivator ACT has been confirmed in human testicular biopsies from patients with obstructive azoospermia (OA), as has its correlation with the expression of transition proteins 1 and 2 (TNP1, 2) and protamines 1 and 2 (PRM1, 2), which are required for the packaging of DNA [31].