Visualization 2: Optically trapping tumor cells to assess differentiation and prognosis of cancers PradhanM. PathakS. MathurD. LadiwalaU. 2016 Real-time movie showing how two ATRA-treated C6 glioma cells that, after 4 s contact, remain adhered to each other. Originally published in Biomedical Optics Express on 01 March 2016 (boe-7-3-943)