Cao et al. (2018) conducted this study to consider the ATP-binding cassette transporter subtype G 2 (ABCG2) as a marker for lung resident MSCs and they observed the transition of these MSCs from an ABCG2-expressing cellular phenotype to a myofibroblast phenotype in a bleomycin-induced mouse fibrosis model. The gene discussed is ABCG2; the disease is fibrosis.