Skin rash (SR) is the most characteristic side effect of erlotinib in PDAC patients.
Erlotinib-induced SR has been associated with a better clinical outcome.
Gene expression profiling was used to determine who will develop this manifestation.
7 genes involved in different pathways were downregulated in PDAC patients with SR.
Our profile correlated with erlotinib-induced SR in PDAC could be used for prognosis.