The same way a rare condition known as eosinophilic leukemia, prompted by a chromosomal rearrangement, referred to as FIP1L1-PDGFRA leads to constitutive activation of the PDGFRA tyrosine domain, bringing patients to full remission within months of imatinib treatment [23, 24]. Here, PDGFRA is linked to Chronic Eosinophilic Leukemia, Not Otherwise Specified.