The following is in response to a query from Dr. Lucy Cherbas on the identity of the cultured cell line used in a number of publications. After asking the various primary authors, I have the following Moutinho-Pereira, S., Stuurman, N., Afonso, O., Hornsveld, M., Aguiar, P., Goshima, G., Vale, R.D., Maiato, H. (2013). Genes involved in centrosome-independent mitotic spindle assembly in Drosophila S2 cells. Proc. Natl. Acad. Sci. U.S.A. 110(49): 19808--19813. Most likely S2U. Uehara, R., Nozawa, R.S., Tomioka, A., Petry, S., Vale, R.D., Obuse, C., Goshima, G. (2009). The augmin complex plays a critical role in spindle microtubule generation for mitotic progression and cytokinesis in human cells. Proc. Natl. Acad. Sci. U.S.A. 106(17): 6998--7003. S2U. Vale, R.D., Spudich, J.A., Griffis, E.R. (2009). Dynamics of myosin, microtubules, and Kinesin-6 at the cortex during cytokinesis in Drosophila S2 cells. J. Cell Biol. 186(5): 727--738. S2U. Goshima, G., Mayer, M., Zhang, N., Stuurman, N., Vale, R.D. (2008). Augmin: a protein complex required for centrosome-independent microtubule generation within the spindle. J. Cell Biol. 181(3): 421--429. S2U. Goshima, G., Nedelec, F., Vale, R.D. (2005). Mechanisms for focusing mitotic spindle poles by minus end-directed motor proteins. J. Cell Biol. 171(2): 229--240. S2U. Goshima, G., Vale, R.D. (2005). Cell cycle-dependent dynamics and regulation of mitotic kinesins in Drosophila S2 cells. Mol. Biol. Cell 16(8): 3896--3907. S2U. Goshima, G., Wollman, R., Stuurman, N., Scholey, J.M., Vale, R.D. (2005). Length control of the metaphase spindle. Curr. Biol. 15(22): 1979--1988. S2U, except for Fig. S5 which used S2I.