SNK analysis revealed that the ratio of radioactivity (tumor/muscle) in C6-sr39TK (3.34 ± 0.70) and C6-TK (3.65 ± 0.74) groups were significantly lower than the control group (4.58 ± 1.10) (q = 4.788, P < 0.05, and q = 3.601, P < 0.05, resp). Here, TKT is linked to neoplasm.