The authors suggested that the lack of survival difference may be related to the high proportion (~80%) of tumors harboring EGFR mutation or ALK translocation among patients with brain metastases in their study [1], as these mutations are known to be associated with favorable response of CNS disease to targeted tyrosine kinase inhibitors and higher response rates to whole brain radiation therapy compared to wildtype lung cancer [36–40]. Here, ALK is linked to lung cancer.