Considering that, worldwide, there is a higher number of SPECT cameras compared to PET, our group reported the synthesis and preclinical evaluation of the [99mTc]Tc-((R)-1-((6-hydrazinylnicotinoyl)-D-alanyl)pyrrolidin-2-yl) boronic acid ([99mTc]Tc-iFAP) as a novel FAP inhibitor radiotracer for SPECT imaging of the tumor microenvironment [19]. Here, FAP is linked to neoplasm.