ACVR2A and infectious otitis media: Significantly lower expressions in the L-AOM in comparison with S-AOM samples were also observed for βB-subunit (93.9 ± 26.7 vs. 167.6 ± 51.1; P = 0.02), ACTRIIA (82.3 ± 17.9 vs. 189.6 ± 57.7; P = 0.03) and smad4 (111.4 ± 25.5 vs. 133.5 ± 32.1; P = 0.03).