Based on the results of the PK/PD study, the efficacy of 100 mg/kg of the PI3K inhibitor GDC-0941 and 1 mg/kg of the MEK inhibitor PD 0325901 given orally, as single agents and in combination, was assessed in HCT116 and HT29 human tumour xenograft-bearing mice (Figure 3). Here, PIK3CA is linked to neoplasm.