PTGS2 and ocular melanoma: The nuclear transcription factor kappa B (NFκB) is the most studied transcription factor in OM because it is an important regulator of proinflammatory cytokine expression (e.g., tumor necrosis factor (TNF)-α and interleukin (IL)-1β, cyclooxygenase-2 (COX-2), as well as matrix metalloproteinases (MMPs).