TWIST1 and neoplasm: To test this, we removed doxycycline for 4 weeks in a cohort of mice (Twist1 OFF) and demonstrated a significant decrease in the number of tumors (93% reduction in tumor number (95% confidence interval 49–151%) Poisson regression, p < 0.001) (Fig. 2D) and size of tumors (a 58% reduction in tumor size (95% confidence interval 18–112%) (linear mixed effects regression, p = 0.002) (Fig. 2E) after the doxycycline was withdrawn.