TAC1 and cancer: Given the importance of NKA in cellular homeostasis and intracellular signaling, impairment or downregulation of NKA activity has been implicated in many pathophysiological conditions, including asthma and allergic diseases, metabolic disorders, cancer, cardiovascular and degenerative brain diseases, as well as neuropsychological disorders [3,6,7,8,9,10,11,12,13,14], as illustrated in Figure 1 and discussed below.