TAL1 and acute lymphoblastic leukemia: Upon megakaryocytic differentiation by TPO, the H3R2 methylation mark is lost for the benefit of the H3K4 methylation increasing the inter alia IL6ST gene expression through the action of the protein arginine deiminase PADI4 at SCL/TAL1 (stem cell leukemia/T-ALL-1)-target gene expression activation [88,89].