Recent data also suggest that other molecular alterations may modulate cancer cell (including PDAC) susceptibility to MAPK inhibition: indeed, PTEN loss was shown to portend intrinsic resistance to MEK inhibitors and synergistic activity of combined MAPK/phosphatidylinositol 3 kinase (PI3K) pathway inhibition [34]; however, combined MAPK/PI3K inhibition did not prove effective in either cell line models of PDAC [35] or PDAC patients [36], presumably owing to the lack of PTEN alterations. The gene discussed is PTEN; the disease is cancer.