SMAD3 and ocular melanoma: Firstly, nontypeable Haemophilus influenzae (NTHi), a known bacterial pathogen involved in human OM, activates Tgfβ receptor-Smad3/4 signaling that together with TLR2-MyD88-TAK1-NIK-IKKβ/γ-IκBα-dependent activation of NF-κB is known to mediate NTHi-induced MUC2 mucin transcription [33].