IRF4 and diffuse large B-cell lymphoma: Given the essential role of IRF4 in ABC-DLBCL and the ability of ROCK2 to phosphorylate IRF4 in T-cells19, we investigated whether IRF4 is aberrantly phosphorylated in ABC-DLBCL by using an antibody that detects the phosphorylation of IRF4 at S446/S447, the ROCK2 phosphorylated residues19.