<s>[INST] <<SYS>> This is a medical question of type : frequency <</SYS>> How many people are affected by PDGFRB-associated chronic eosinophilic leukemia ? [/INST] The exact prevalence of PDGFRB-associated chronic eosinophilic leukemia is unknown. For unknown reasons, males are up to nine times more likely than females to develop PDGFRB-associated chronic eosinophilic leukemia. </s>