While high selectivity of molecular probes would be essential for targeting a biomolecule isoform that has a variety of functions and exists at comparable expression levels in close proximity to other isoforms, for FABP4 selectivity may not be as high a priority given that this isoform is expressed in lesions such as glioblastoma and atherosclerosis, while other FABP isoforms are expressed in surrounding organs. The gene discussed is FABP4; the disease is glioblastoma.