KLF4 and cardiovascular disorder: Formononetin: Formononetin is the primary flavonoid constituent obtained fromastragalus and exhibits protective effects against cardiovascular diseases [37, 38] and suppressive effects on the development of AS, such as obesity [39, 40].It can downregulate the expression of SR-A by modulating Kruppel-like factor 4 (KLF4), thus,significantly reducing the cholesterol uptake levels in human VSMCs andinhibiting the generation of VSMC-derived foam cells [16] (Table 1, Ref.