PLCG2 and B-cell chronic lymphocytic leukemia: Three distinct PLCg2 mutations were found in CLL patients with resistance to ibrutinib therapy: arginine-to-tryptophan mutation at position 665 (R665W), leucine-to-phenylalanine at position 845 (L845F), and a serine-to-tyrosine mutation at position 707 (S707Y) [9].