Immunoblot analysis revealed that, as in A-1 cells, the phosphorylation level of MEK was increased in SHP-2 (G503V)-expressing cells as well as in cells derived from a tumor formed by these cells (SHP-2 (G503V)-3 cells), whereas MEK phosphorylation in BRAP (G370A)- or SHP-2 (G503V)/BRAP (G370A)-expressing cells did not differ from that in parental cells (Figure 4A). Here, PTPN11 is linked to neoplasm.