Employing stringent statistical approach (p < 5 × 10−4), we report a high association between MUC5B rs35705950*T and IPF susceptibility in all the four analyzed populations among Czechs: [OR (95% CI) p] 3.77 (7.47–1.9) 1.62 × 10−4, Germans: 4.83 (9.79–2.39) 1.55 × 10−5, Greeks: 5.46 (10.82–2.76) 1.13 × 10−6, and French: 6.77 (12.65–3.62) 5.28 × 10−10 along with all patients from this study as a whole: 5.23 (8.94–3.06) 1.80 × 10−11. This evidence concerns the gene MUC5B and idiopathic pulmonary fibrosis.