To confirm the effectiveness and selectivity of this compound, we precipitated LMWPTP and two other phosphatases with activity towards the substrate PNPP (SHP-1 and PTP1B) from CRC cells and demonstrated that the phosphatase activity of LMWPTP was indeed decreased in the presence of PLP, while the activity of SHP-1 and PTP1B were unaffected (Figure 3A and Supplementary Figure S2A). The gene discussed is PTPN1; the disease is colorectal carcinoma.