The present invention relates generally to the treatment and prevention of diseases characterized by excess cell proliferation and/or activation. In particular, the present invention provides compositions and methods to suppress the activation and/or proliferation of various cells. In preferred embodiments, the present invention provides compositions and methods to suppress the activation and/or proliferation of mesenchymally derived cells (including, but not limited to hepatic stellate cells), as well as cells with abnormal growth characteristics. In particularly preferred embodiments, the present invention provides compositions and methods to inhibit or eliminate fibrosis. In alternative preferred embodiments, the present invention provides compositions and methods to induce fibrosis.