Further diagnostic work-up entails screening on peripheral blood for the most common genetic lesions involved in clonal eosinophilia: BCR-ABL, JAK2V617F, FIP1L1-PDGFRA, ETV6-PDGFRB gene fusions, KITD816V mutation, and T cell receptor (TCR) clonal rearrangement. The gene discussed is PDGFRA; the disease is Increased total eosinophil count.