FOLR2 and neoplasm: This may interfere with the interpretation of receptor expression in lesions close to these organs and for this reason, small quantities of folic acid are injected prior to 99mTc-etarfolatide administration in order to partially saturate the FRαs.67 Another limitation of this probe conjugate stems from activated macrophages (that express FRβ) also internalising 99mTc-etarfolatide, a phenomenon which can result in regions of inflammation or infection falsely appearing as FRα-positive tumour tissue.67