Comparison of RNA expression of the nine human LIV-1 family members in antihormone-resistant MCF-7 cells. The expression of different ZIPs in tamoxifen (TamR)- and fulvestrant (FasR)-resistant MCF-7 cells was compared with wild-type MCF-7 cells. RNA was extracted and reverse transcribed to cDNA. The upper panel shows representative gels of pS2, LIV-1, HKE4, and ZIP8 in MCF-7 (lane 1), TamR (lane 2) and FasR (lane 3) cell lines. M represents size markers. Lower panel shows mean ± SEM densitometric values of 8 genes comparing their expression levels in MCF-7, TamR, and FasR cells. Statistically significant results are indicated with asterisks, and the relevant P value is given. ZIP4 was undetectable.