RXRA and Lassa fever: In contrast, overexpression of RXRα in HSCs in vitro can inhibit the secretion of α-smooth muscle actin (α-SMA) and collagen I in HSCs, while in vivo overexpression of RXRα could resolve LF in mice, suggesting that this nuclear receptor plays a key role in the activation of HSCs and in LF (Ohata et al., 1997; Wang et al., 2011).