In this study, we report on the validation of a custom NGS panel which targets 22 MPN-associated genes (ABL1, ASXL1, CALR, CBL, CEBPA, CSF3R, DNMT3A, EZH2, FLT3, IDH1, IDH2, JAK2, KIT, MPL, NPM1, PDGFRA, RUNX1, SF3B1, SRSF2, TET2, TP53, and U2AF1) by using a set of reference standards and a small cohort of clinical MPN samples. The gene discussed is FLT3; the disease is myeloproliferative neoplasm.