Likewise, the activation and translocation of transcription factor, nuclear factor-κB (NF-κB), from the cytosol to the nucleus is one of the key elements in the initiation of 5-FU-induced mucositis that leads to the upregulation of genes and the subsequent production of pro-inflammatory cytokines such as tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, and IL-6 [2,11], cyclooxygenase (COX)-2 [12], and high-mobility group box 1 protein (HMGB1) [13]. This evidence concerns the gene NFKB1 and mucositis.