EGFR and neoplasm: Quantitative PET molecular imaging, coupled with selective labeled biomarkers, may facilitate in vivo EGFR-targeted drug efficacy by noninvasively assessing expression of EGFR in tumor, guiding dose and regime by measuring target-drug binding, receptor occupancy, and duration of inhibition, as well as potentially detecting the existence of a primary or secondary mutation leading to either drug interaction or failure of EGFR recognition by the drug.