We measured the levels of SLPI, hyaluronic acid (HA), soluble mesothelin-related peptides (SMRP), CCL2, galectin-3, and CYFRA21-1 in 51 patients with BAPE, 37 patients with early-stage MPM, 77 patients with pleural effusions due to non-small-cell lung cancer (LCa), and 74 patients with other pleural effusions. The gene discussed is MSLN; the disease is Pleural effusion.