Overview of canonical and noncanonical pathways of transforming growth factor (TGF)-β signaling in fibrosis. AKT, protein kinase B; ECM, extracellular matrix; LIMK, LMK kinase; PI3K, phosphoinositide 3-kinase; Rho, Ras homolog family member; SMA, smooth muscle actin; TGFR, TGF receptor.