GAK and incontinentia pigmenti: The low frequency of occurrence of IP as an adverse effect of gefitinib therapy and the presence of missense mutations in the GAK coding region (http://www.ncbi.nlm.nih.gov/projects/SNP/snp_ref.cgi?locusId=2580) also suggest that SNPs may become useful prognostic markers, which will be the focus of our future work.