Blebbistatin, a myosin inhibitor, is phototoxic to human cancer cells under exposure to blue light

► The study shows blebbistatin as a potential photodynamic drug to kill cancer cells. ► Extent of the photodynamic effect varies for different cell lines. ► During light exposure blebbistatin generates ROS but not singlet oxygen. ► Blebbistatin is photodegraded along with the formation of its photoproducts.