TMEM97 and Niemann-Pick disease, type C1: TMEM97 is the recently identified σ2 receptor (Alon et al., 2017) that binds to the intracellular cholesterol trafficking protein NPC1 (Niemann-Pick disease, type C1), reducing its abundance and in turn cholesterol transfer to the ER (Ebrahimi-Fakhari et al., 2016).