HSP90B1

Heat shock protein 90kDa beta member 1 (HSP90B1), known also as endoplasmin, gp96, grp94 and ERp99, is a chaperone protein that in humans is encoded by the HSP90B1 gene.

HSP90B1 is an HSP90 paralogue that is found in the endoplasmic reticulum. It plays critical roles in folding proteins in the secretory pathway such as Toll-like receptors and integrins. It has been implicated as an essential immune chaperone to regulate both innate and adaptive immunity. Tumor-derived HSP90B1 (vitespen) has entered clinical trials for cancer immunotherapy.