JAK2 and triple-negative breast carcinoma: A subset of lymphomas, triple-negative breast cancers, and Epstein Barr Virus-positive gastric cancers are associated with genomic amplifications of a region of chromosome 9 containing PD-L1, PD-L2, and JAK2 loci termed the PDJ amplicon.19–21 These malignancies harboring the PDJ amplicon exhibit increased levels of PD-1 ligand and JAK2, while JAK2 inhibition was shown to decrease PD-1 ligand expression.