ACTA1 and Lassa fever: In hypertrophic LF, fibrosis-related factors, such as TGF-β1 (191), α-smooth muscle actin (α-SMA) (188), CoL1a1 (192), IL-6 (193), and MMP2 (189), are upregulated, and they reportedly promote the loss of elastic fibers during LF tissue degeneration.