EGFR and neoplasm: In the context of PET imaging of mutant forms of EGFR, one of the first examples of irreversible TKI reported in the literature is [18F]PEG6-IPQA; [18F]PEG6-IPQA was shown to bind with higher selectivity and specificity to L858R activating mutant EGFR expressing tumour xenografts compared to resistant EGFR L858R/T790M mutant xenografts [19].