The aims of the current investigation were to determine whether functional polymorphisms in the tumor necrosis factor-alpha (TNF-alpha) gene at position -308; in the transforming growth factor-beta 1 (TGF-beta1) gene at positions -509, +869 (codon 10), and +915 (codon 25); in the interleukin-10 (IL-10) gene at position -1,082, -819 and -592; and in the intron 1 of the interferon-gamma (IFN-gamma) gene at position +874 are associated with silicosis and PTB.