Moreover, a high frequency of EMD in APL may also be related to the ATRA-induced upregulation of G-CSF receptors in APL cells, making them more sensitive to endogenous or exogenous G-CSF effects.15 Other described sites of EMD in APL include: the testes, sites of vascular access, external ear and auditory canal, lung, pleura, heart, lymph nodes, mediastinum, thymus, spine, breast, pelvis, mandible and gingiva, bowel. Here, CSF3 is linked to acute promyelocytic leukemia.