MKI67 and neoplasm: Consistently, only 1 of 3 FRTL5-Ras-PATZ1 tumors analyzed, excised at the end of their growth observation, showed Ki67 positivity against 3 out of 3 from control group, even though no significant differences in Ki67 tumor expression—likely due to the low number of specimens analyzed—was detected in the two cohorts of mice (Figure 1c).