HSPA4L and infectious otitis media: Other PDIA2-interacting proteins included 14 ER stress–associated proteins functioning in protein folding [P4HB, DNAJC3, HSPBP1, DNAJB1, DNAJA2, and HSPA4L), protein secretion processing (LMAN1, SAR1B), misfolding protein degradation (DERL1), antioxidant (TXNDC5), and calcium homeostasis (CANX) (Figure 3C; Supplement Table S8)], demonstrating a typical unfolded protein response (UPR) in response to AOM/DSS stimulation.