PRL and neoplasm: To elucidate the correlation between miR-21-5p and PRL invasiveness, we defined invasive PRL (Y value set as 1) in 4 of the 12 samples in which the tumor broke through its capsule and invaded the cavernous sinus and noninvasive PRL (Y value set as −1) in the other 8 samples in which the PRL did not invade the cavernous sinus, and the correlation between the expression of miR-21-5p, and the invasive phenotype was calculated using the Spearman correlation statistics.