GJA1 and type 2 diabetes mellitus: In line with a lower severity of testicular damage in T2D males, we found only a few expression changes, particularly, altered expression of cell junction proteins, e.g. gap junction protein Cx43 in Leydig cells, and blood-testis-barrier components, tight junction protein, claudin 11 (74), and the adhesion junction component, cadherin 2 (75).