CHAC1 and head and neck squamous cell carcinoma: The mechanisms of action observed by Akbari & Avand [16] were initially validated by an in vivo study assessing the activity of nisin against head and neck squamous cell carcinoma (HNSCC) cell lines, in which this gut metabolite inhibited tumourigenesis via multiple mechanisms of action, including the activation of cation transport regulator homolog 1 (CHAC1), the induction of cell cycle arrest and the initiation of apoptosis, and increased calcium efflux [54].