On mice with KB (FR-α-positive) and A549 (FR-α-negative) implanted shoulder tumors, 99mTc-DMTHF was taken up by the KB tumor but not the A549 tumor, demonstrated by radioisotope imaging and biodistribution analysis [REF].
In an atherosclerosis model where macrophages accumulate, 99mTc-EC20, but not 99mTc-DMTHF, was taken up in the aorta-cardiac region [REF].