BRD2 and infectious otitis media: Consistent with the in vitro results, in the AOM/DSS-induced murine orthotopic CC model, intraperitoneal injections of EVs derived from wild-type MC38 cells (M+ EVs) into tumor-bearing mice dramatically increased the mtDNA content and coexpression of Nd1, Cytb, and Cox1 in NAT, while injection of mtDNA-depleted EVs (M− EVs) derived from MC38-ρ0 cells strongly attenuated this effect (Fig. 5d–f).