Recently, Van den Bogaard and colleagues described a family with autosomal recessive hypotrichosis and dry skin caused by homozygous nonsense variant c.361C > T in CST6, resulting in the expression of truncated and only partly functional cystatin M/E that lacked the inhibitory function for cathepsins V and L and legumain (van den Bogaard et al., 2019). This evidence concerns the gene CST6 and hypotrichosis.