TGFB1 and infection: Meanwhile, we observed that miR-21 mimics caused a noticeable increase in the mRNA transcript and protein levels of ERK1 and RSK2. In addition, AdSPRY2 infection of primary HSCs treated with TGFβ1 for 48 h suppressed the expression of miR-21 accompanied by a marked decline in the mRNA transcript levels of ERK1 and RSK2 (Fig. 3D), whereas miR-21 level slightly increased after primary HSCs were transfected with siRNA against SPRY2 (Fig. S3).