Transmission spectrum of GJ 3470b from the near ultraviolet to the infrared, with all published values reported: LBT measurements at 357.5 and 963.5 nm (blue; Nascimbeni et al. 2013), OAO telescopes visible and near-infrared broad-band measurements (green; Fukui et al. 2013), near-infrared HST/WFC3 spectroscopic measurements (orange to dark red; this work), Keck/MOSFIRE narrow-band measurements (violet; Crossfield et al. 2013), and Spitzer/IRAC broad-band photometry at 4.5 μm (black; Demory et al. 2013). The dashed and dotted lines show the white light curve radius ratio and its ± 1σ uncertainty, respectively.