Similarly, smaller association studies have identified four loci associated with UM (Ferguson et al. 2016; Mobuchon et al. 2017, 2022; Thomsen et al. 2020), with three overlapping CM susceptibility regions, including the loci at IRF4 and HERC2/OCA2 linked with pigmentation and the TERT/CLPTM1L locus associated with telomere regulation (Derrien et al. 2022). This evidence concerns the gene OCA2 and cutaneous mastocytosis.