PKD2 and B-cell chronic lymphocytic leukemia: In CLL cells, anti-IgM stimulation resulted in phosphorylation of Ser744 and/or Ser748 residues positioned in the activation loop of the PKD2 and PKD3 kinase domains and of Ser916 residue, a site of auto-phosphorylation present in the PKD2 isoform only [22–24, 28].