ALK and lung cancer: EGFR is a part of the ErbB family of transmembrane receptor tyrosine kinases, which mutate in some lung cancers.[5] EML4-ALK fusion occurs in ∼3% to 5% of non-small cell lung cancer.[6] In the presence of EGFR and/or ALK gene mutations, there is a choice between EGFR TKI drugs or ALK inhibitors for anti-tumor treatment.