The paths treatment PI3K of the relevant pathological condition of biomarker, such as cancer, and using the paths upstream component PI3K such as PI3K- α AKT inhibitor or the inhibitor of inhibitor, be described. Especially, describe the method that biomarker patient selects treatment malignant tumour, and treatment, diagnostic kit and its method of detection, wherein cancer possesses the PI3K approach (such as PIK3CA genes and/or AKT genes) and wild type MAP3K1 genes and MAP2K4 genes of a mutation upstream component, is more likely to successfully respond the upstream component PI3K approach of processing and inhibitor.