PTPRO and B-cell chronic lymphocytic leukemia: Notably, it has been observed that the elevated level of phosphorylation in CLL cells can be accounted for by the impaired expression or activity of a significant number of protein or lipid phosphatases, including protein tyrosine phosphatase receptor type O (PTPROt) [42], PH Domain and Leucine Rich Repeat Protein Phosphatase 1 (PHLPP1) [43], Src homology (SH) 2 (SH2) domain containing inositol polyphosphate 5-phosphatase 1 (SHIP1 [44,45], Phosphatase and tensin homolog (PTEN) [46,47], and Protein Phosphatase 2A (PP2A) [38,48].