REN and hand, foot and mouth disease: Consequently, this can lead to cardiac failure and cardiogenic shock.[4] Zhang et al showed a significant elevation of substances from renin-angiotensin-system (RAS) and noradrenalin in children with moderate to severe HFMD compared to healthy control children.[14] In addition, mouse experiments have revealed a correlation between RAS-associated chemicals, noradrenaline, and the severity of HFMD.