MBTPS2 and Palmoplantar keratoderma: TRPV3 regulated by mutated MBTPS2 or directly mutated TRPV3 might function in a dominant‐positive manner to increase constitutive TRPV3 activity and elevate Ca2+ in keratinocytes, leading to severe keratoderma (Lin et al., 2012; Nemer et al., 2017).