CNPY3/PRAT4A is a Toll-like receptor (TLR) -specific co-chaperone of HSP90B1 and is essential for correct TLR folding (except TLR3) . It ensures controlled TLR exit from the endoplasmic reticulum, affecting innate and adaptive immune responses. CNPY3/PRAT4A Protein, Human (HEK293, Fc) is the recombinant human-derived CNPY3/PRAT4A protein, expressed by HEK293 , with C-hFc labeled tag.