As a nuclear transcription factor, NF-κB, which consists of P50 (NF-kB1), P52 (NF-kB2), REL (also known as cREL), P65 (REL-A) and REL-B, drives the transcription of numerous genes associated with the resistance of apoptosis for tumor cells, such as inhibiting apoptosis inhibitors (IAPs), BCL-2, Bcl-xL, Cox-2, matrix metalloproteinases (MMPs), tumor necrosis factor (TNF) receptor-associated factors 1 and 2 (TRAF1, TRAF2), survivin, and XIAP. Here, REL is linked to neoplasm.