MBTPS2 and alopecia: Mutations to membrane-bound transcription factor peptidase site 2 (MBTPS2), which facilitates the cleavage of sterol regulatory element-binding protein 2 (SREBP2), are involved with ichthyosis follicularis, alopecia and photophobia (IFAP) (Jiang et al. 2019) as well as keratosis follicularis spinulosa decalvans (KFSD) (Zhang et al. 2016), resulting in non-progressive alopecia and cicatricial alopecia, respectively.