A total of 180 variant groups were defined to denote logical grouping of biomarkers with generalisable clinical significance [e.g., EGFR exon 19 deletions in non-small cell lung cancer (NSCLC)], including generic concepts of functional consequence of genetic alteration based on molecular pathology assessments (e.g, “oncogenic” or “gain-of-function” mutations). The gene discussed is EGFR; the disease is non-small cell lung carcinoma.