AK2 and neoplasm: No significant association was detected between AK2 expression and patient age (≤60 vs >60 years, P = 0.655), gender (male vs female, P = 0.284), tumor size (<3 cm vs ≥3 cm, P = 0.137), smoking (smokers vs non-smokers, P = 0.191), or pleural involvement (yes vs no, P = 0.177) (Table 1).