The plasma levels of 7-KC have significant correlations with different levels of disease severity of NP-C1 patients (Porter et al., 2010; Stampfer et al., 2013), and the decrease of 7-KC was beneficial to NPC1 mutant feline model after treated by HPβCD (Porter et al., 2010). This evidence concerns the gene CALCA and Niemann-Pick disease, type C1.