Sumitra's work has led to the prospective identification of retinal stem cells/progenitors and the involvement of CNTF-mediated signaling as a molecular switch for neuronal versus glial differentiation of the late retinal stem cells/progenitors. Using Hoechst dye efflux assay, Sumitra isolated retinal stem cells/progenitors from fresh embryonic retina and demonstrated that their properties and differentiation potential are similar to those enriched from mitogen-dependent neurosphere culture, suggesting that both prospectively and retrospectively isolated retinal stem cells/progenitors are equally suitable for therapeutic use. Currently, she is examining the role of ABCG2, the molecular basis for Hoechst dye efflux, in the maintenance of retinal stem cell/progenitor homeostasis. Her studies show that signaling that maintains stem cells, such Notch signaling, regulate ABCG2. Recently, she showed that the bHLH transcription factor, Ath3 plays a role in CNTF-mediated differentiation of retinal stem cells/progenitors into bipolar cells. CNTF also influences their differentiation into Muller glia. Sumitra has proposed and confirmed that it is the differential utilization of distinct intracellular paths, in response to different CNTF concentrations that allows CNTF to act as a molecular switch for neuronal versus glial differentiation.