TGFB3 and fibrosis: Interestingly, compared with WT rats, however, the expression of TGF-β3 around pulmonary granulomas in KO rats showed nearly a 64% reduction on day 7 (P<0.01) and 67% increase on day 14 post-challenge (P<0.05) (Fig 6E and 6F), which is opposite to the trend observed in pulmonary granuloma associated fibrosis.