KLF4 and asthma: At the cellular level, human ASM cells treated with TNF-α, IL-1β, and IFN-γ (imitate the inflammatory conditions in patients with asthma) induced an up-regulation of miR-145-5p and a down-regulation of Krüppel-like factor 4 (KLF4), an inhibitor of smooth muscle cell proliferation [59].