SCGB1A1 and fibrosis: Club cell depletion is also associated with 15 or 17 Gy radiation exposure to the whole thorax (32, 40) and plasma CCSP (club cell secretory protein) can be used as a marker for adverse radiation outcome and, especially, for fibrosis development in fibrosis-prone C57 mice [5 Gy total body + 10 Gy to the whole lung (41)], suggesting in this and in previously published work that loss of club cells may signal fibrosis development (12).