ERBB2 and breast neoplasm: Other microarray data also indicated that the expression of ErbB2 is lower in TNBC cell lines than in non-TNBC cell lines despite both PKCα and uPAR being higher in TNBC cell lines [37], thus suggesting that MZF-1/Elk-1 heterodimers may be upstream for PKCα in PKCα-overexpressing TNBC cells, a parallel position to ErbB2 in ErbB2-overexpressing breast tumors.