While our results of altered anti‐BIRC5 IgG levels in NSCLC are consistent with the previous studies 12, 24, this IgG antibody cannot serve as a biomarker for early diagnosis of NSCLC as plasma anti‐BIRC5 IgG levels were not significantly changed in patients with early‐stage NSCLC (Table 6). Here, BIRC5 is linked to non-small cell lung carcinoma.