PADI4 and myeloid leukemia: Expression of the Peptidylarginine deiminase 4 (PAD4) was first detected in human myeloid leukemia HL-60 cells after ATRA and 1alpha,25-dihydroxyvitamin D(3)-induced differentiation, and it was observed to regulate hematopoietic progenitor proliferation [6, 7].