Fig. 3.

Extracellular signaling regulates fibrosis. The process of fibrosis induced by ionizing radiation is mediated by several extracellular molecules. One of the most important groups is the cytokine family, TGF-β, an important factor in the regulation of fibrosis, which can be involved in regulating the expression of fibrosis-related genes through Smad-dependent and Smad-independent pathways. In addition, extracellular Wnt signaling pathway may also be involved in regulating fibrosis gene expression by activating intracellular β-catenin signaling pathway. Cytokines such as IL-1β and IL-10 are also involved in regulating fibrosis gene expression. (Figure was created with https://www.Biorender.com)