ERBB2 and neoplasm: These results agree with those reported by Cheng et al. who noted that s.c. HER2-positive SUM190 tumor xenografts were imaged by either microSPECT or microPET using trastuzumab conjugated to biotinylated 99 mTc- or 18F-labeled phosphodiamidate morpholinos (MORFs) through a streptavidin linker [28].