JAK1 and breast cancer: In addition, all BC subsets showed an increased expression of genes associated with an inflammatory state, including NFKBIA, JUN, and COX5A. Moreover, we identified subtype-specific expression patterns, including KLF6 and HSPA5 in ABCs; XBP1, IRF4, JAK1, and IGHA1 in PCs; and BACH2 and IGHV4-34 in naive BCs (NBCs) (Fig. 3d).