Several genetically encoded FRET-based fluorescent biosensors have been developed to monitor aberrant kinase activity associated with cancer, such as Bcr-Abl biosensor Pickles implemented to measure hyperactivity of this kinase in cells from patients with chronic myelogenous leukaemia (CML) and evaluate kinase inhibitor efficacy, response to therapy and onset of resistance or the Src biosensor applied to study spatial control of Src in pancreatic cancer by means of intravital FLIM-FRET imaging [58,59,60,61,62,63,64]. Here, SRC is linked to cancer.