The pathogenesis of BIA-ALCL, which involves genetic predisposition, mainly includes JAK-STAT, DNA methyltransferase 3 alpha (DNMT3A) mutation, tumor protein p53 (TP53) mutation, programmed cell death 1 ligand 1 (PD-L1) chromosomal copy number aberrations (CNAs), chromosome 20q loss, and the overexpression of carbonic anhydrase 9 (CA9). The gene discussed is CA9; the disease is anaplastic large cell lymphoma.