Malmlöf introduces a fundamental concept: they show that in hepatocarcinoma the phosphorylation of MDM2 on serine 166 is dependent on the activation of the MAPK pathway; in fact it, is inhibited by the action of PD98059 or U0126 (MEK inhibitors), but not by LY-294002 or Wortmannin (PI3K inhibitors), while the reverse occurs in lung cancer, as whether this phosphorylation appears depends on the PI3K pathway [71]. The gene discussed is MDM2; the disease is lung cancer.