In our study, using multivariate logistic regression, VEGF [odds ratio (OR): 2.46, P = 0.01], TNF-α (OR: 3.64, P = 0.04), and C3 (OR: 3.77, P = 0.02) levels were identified as the independent risk factors for pleural effusions. The gene discussed is C3; the disease is Pleural effusion.