PROM1 and metastatic malignant neoplasm in the lymph nodes: Data are presented as median and interquartile range. CD133 - prominin-1. HIF-1α - hypoxia-inducible factor-1α. LNM - lymph node metastasis. MPE - malignant pleural effusion. P - pleural fluid concentration. S - serum concentration. P < 0.05 was considered statistically significant.