TGFB1 and ocular melanoma: A rat model of OM involving dual infection of the middle ear with NTHi and Pneumococcus type 6A (Pn6A) demonstrated upregulation of genes encoding inflammatory Th2 cytokines and effectors of the TGF-β signalling pathway, which resulted in pathogenic changes and thickening of the mucosa and submucosal layers of the middle ear during OM (Lee et al., 2011).