A number of studies have shown that BCR‐ABL1 is itself involved in the production of VEGF in CML cells.51, 53, 54 In addition, BCR‐ABL1 has been implicated in the production of histidine decarboxylase (HDC) and thus in the synthesis of histamine in CML cells.68 However, not all angiogenic and fibrogenic cytokines are produced in CML cells in a BCR‐ABL1‐dependent manner. The gene discussed is HDC; the disease is chronic myelogenous leukemia, BCR-ABL1 positive.