Because ST is most likely a tumor-independent AE mediated by anti-EGFR antibody treatment, we hypothesized that single nucleotide polymorphisms (SNP) which are known to be related to other ST like acne [19–21], systemic lupus erythematodes (SLE) [22], or FcRγ-signaling [23, 24] might also be indicative for anti-EGFR treatment related ST. Here, FCER1G is linked to systemic lupus erythematosus.