Since CM-related SJS/TEN with SOC is a rare condition with a complex genetic background, it is reasonable to posit the presence of multiplicative interactions of HLA and susceptibility genes such as HLA-A and TLR3 (Ueta et al., 2012a), HLA-A and REC14 32, and HLA-A and PTGER3 (Ueta et al., 2015b), and it is possible that multiple susceptibility genes for CM-related SJS/TEN with SOC are involved in forming functional networks. This evidence concerns the gene PTGER3 and cutaneous mastocytosis.