SPNS1 and lysosomal storage disease: SPNS1 encodes a lysosomal efflux transporter that regulates mTOR signaling and whose loss‐of‐function is associated with lysosome storage disorders (Nakano et al, 2001; Dermaut et al, 2005; Rong et al, 2011; Sasaki et al, 2014; Yanagisawa et al, 2017).