CNTN2 and cancer: Notably, while affecting cell viability, AXT IC50 was not reached at concentrations over 100 μM in gastric cancer cell lines [43], suggesting that while AXT indeed acts as a proapoptotic agent in cancer, as has been suggested by several in vivo experiments in mice [44,45,46], their outcome might be moderate when investigated in cancer cell lines as treatments are limited in concentration and time.