RPIA and Azoospermia: In non-obstructive azoospermia, ribose 5-phosphate isomerase A (RPIA) gene expression increased (upregulation), while ribosomal modification protein rimK-like family member B (RIMKLB), L-2-hydroxyglutarate dehydrogenase (L2HGDH), and hydroxysteroid 17-beta dehydrogenase 7 (HSD17B7) gene expression decreased (downregulation).