The ciliary-targeting signal (CTS) VxPx is a hotspot for mutations that interfere with rhodopsin transport, causing severe forms of autosomal dominant retinitis pigmentosa (adRP) and blindness (Aleman et al., 2008; Berson et al., 2002; Bessant et al., 1999; Sullivan et al., 2006). The gene discussed is RHO; the disease is autosomal dominant retinitis pigmentosa.