HSP90B1 and glaucoma: Unlike a typical client, stability-compromised mutant myocilins12,13 are not triaged for degradation by Grp94 (Fig. 1C), but rather co-aggregate with the chaperone, leading to further accumulation14,15, ER stress, and cytotoxicity6,16–18 that ultimately propagate to glaucoma-associated vision loss19,20.