Erlotinib (Tarceva®, OSI-774; Roche Life Science, Indianapolis, IN) was purchased from LC Laboratories (Woburn, MA) and dissolved in 100% dimethyl sulfoxide (DMSO; Sigma, St. Louis, MO). We chose doses of Erlotinib from the literature that were previously used in cell culture experiments (Cao et al., 2006 (link); Petty et al., 2004 (link); Ware et al., 2013 (link); Wertheimer et al., 2013 (link)). Erlotinib was added to culture media to produce two final concentrations of 100nM and 1μM. We added the same volume of solvent (DMSO) to all samples, vehicle, and staurosporine (positive control for cell death; Enzo Life Sciences, Farmingdale, NY).