TRPV3 and Hyperkeratosis: The atypical activity of TRPV3 channels leads to greater epidermal thickness in the layer of stratum corneum (hyperkeratosis), granular layer (hypergranulosis), stratum spinosum, and stratum basale (Figure 1B), consistent with previous studies (Asakawa et al., 2006; Yoshioka et al., 2009).