MUC5B and pulmonary fibrosis: Compared to many other animal models of pulmonary fibrosis [24,25], the conditional knockout of Nedd4-2 in adult mice shares several important features with IPF, and these include the insidious development of the disease, the distribution and pattern of lesions (e.g., honeycombing) and the accumulation of Muc5b in distal parts of the lung [26], just to name a few.