TNFRSF10B and neoplasm: Following treatment of COLO205 tumors with a TRAIL-R2 agonist, the increase in tumor-to-muscle (T/m) contrast generated by 68Ga-C2Am was 2.3 ± 0.4, which was lower than that observed previously for 18F-C2Am (6.1 ± 2.1) [31], but identical to the contrast observed previously for the SPECT agent 111In-C2Am (2.2 ± 0.2) [29].