ARHGEF3 and idiopathic pulmonary fibrosis: To support the noncanonical function of ARHGEF3 as a mTORC2 regulator, ARHGEF3 has been reported to control the regulation of the mTORC2-secreted protein acidic and rich in cysteine (SPARC) axis in idiopathic pulmonary fibrosis (Kamio et al., 2017).