IL2 and infection: EV71 infection triggers a systemic inflammatory response, leading to an increased expression of tumor necrosis factor α (TNF-α), TNF-β, and other factors that promote inflammatory infiltration of cardiomyocytes (Ding et al., 2015; Wu, 2020), and the infection significantly promotes the expression of inflammatory factors such as interleukin 2 (IL-2) and IL-4 in thymocytes (Chung et al., 2008; Wu, 2020).