By definition, there should be no Philadelphia chromosomeor a rearrangement involving PDGFRA/B andFGFR12.The second group falls under the category of myeloid/lymphoid neoplasms witheosinophilia and rearrangement of PDGFRA, PDGFRB,or FGFR1, or with PCM1-JAK2. The gene discussed is PDGFRA; the disease is lymphoid neoplasm.