Use of phospho-Akt as a biomarker for predicting the response, such as resistance, to a compound, wherein phospho-Akt is Akt that has been phosphorylated on one or more residues, with the proviso that for Akt1, Akt2, and Akt3 the designation phospho-Akt is used to indicate phosphorylation at a site other than T308, T309 or T305 respectively, wherein the compound is a compound of general formula (I).