The multifactorial comparison of patients with slow and rapid progression forms of IPF included age ≤ 55 years, age ≥ 65 years, male gender, smoking history, antifibrotic therapy (Nintedanib, Pirfenidone, or no therapy), HLA alleles/haplotypes (HLA-DRB1*04:05; HLA-A*01:01, DQB1*03:01; HLA-A*02:01, DQB1*02:01; HLA-B*49:01, C*07:01; HLA-A*30:02, B*18:01, C*05:01; HLA-A*30:02, B*18:01, C*05:01, DQA1*05:01, DQB1*02:01, DRB1*03:01). The gene discussed is HLA-A; the disease is idiopathic pulmonary fibrosis.