PDIA3 and male infertility: ERp57 is accepted as a possible biomarker for male infertility.[2] Accompanied with calnexin and calreticulin, ERp57 helps in regulating glycoprotein folding that is an important process in sperm functioning.[6] Basically, ERp57 acts as a chaperone for Ca2+ regulation within endoplasmic reticulum.[7–8] Hence, ERp57 is very important for any motile cells including spermatozoa.