FOS and cancer: In EA-derived TNBC lines, a strong overabundance of motifs associated with members of the AP-1 TF families was observed, including members of the FOS (FOSL1, FOSL2, FOS), JUN (JUND, JUN, JUNB), and ATF (BATF) and MAF (MAF) subfamilies; AP-1 proteins are bZip domain-containing TFs that homodimerize and heterodimerize with each other and are implicated in cancer cell growth and proliferation across a number of cancer types, including breast (31).