A significant decrease in the frequency of the heterozygous AG genotype of the SNP rs2227956 of HSPA1L gene (OR = 0.26, 95 % CI = 0.09–0.72, Pc = 0.01,) and in the frequency of the homozygous AA genotype of the SNP rs1061581 of the HSPA1B gene was also found in the IPF group (OR = 0.30, 95 % CI = 0.13–0.57, Pc = 0.001) when compared to the control group. This evidence concerns the gene HSPA1B and idiopathic pulmonary fibrosis.