MTOR and neoplasm: mTOR has been shown to be required for proliferation of Müller glia progenitors in response to injury in chick retina.36 While multiple signaling pathways most likely drive proliferation and tumor growth in the Tg(flk1:RFP)is18/+ model, our data are consistent with our previous analyses which suggest that mTOR signaling could influence activation of Müller glia regeneration pathways in the Tg(flk1:RFP)is18/+ retina.