A systematic review and meta-analysis has provided secondary-level evidence supporting the association between the loss of expression of the retinoblastoma protein (pRb)—which exerts its tumor suppressor function by binding and inactivating E2F transcription factors, thereby blocking entry into the S phase and preventing uncontrolled cell cycle progression [60,61,62,63,64,65,66]—and a significantly elevated risk of malignant transformation in OL (RR = 2.00; 95% CI: 1.22–3.29) [42]. Here, RB1 is linked to neoplasm.