Dermatologists are frequently asked to see patients with pustular eruptions caused by EGFR mAbs or tyrosine kinase inhibitors. In this issue, Campbell et al. describe an infant with severely inflammed skin and bowel and lung disease caused by a homozygous mutation in the EGFR gene. This commentary discusses the power of exome sequencing in disease gene discovery within the rare genodermatoses and the role of aberrant EGFR signaling in a subset of monogenic skin and epithelial syndromes.