MTOR and cancer: We examined a subset of cell lines from four primary sites (lung, breast, skin and aerodigestive tract; epithelial tissues known to be regulated by epidermal growth factor receptor (EGFR) family members (11)) for their sensitivity to drugs annotated by any of six cellular processes and pathways relevant to cancer (apoptosis regulation, cell cycle, EGFR signaling, ERK MAPK signaling, PI3K/MTOR signaling, and RTK signaling) using the activity area metric—the area above the dose response curve that increases with both drug efficacy and potency (Figure 3A).