Effects of ATRA on HEX expression and localization in MCF-7 cells. HEX protein and HEX mRNA levels were evaluated by immunohistochemistry and real time PCR, respectively. A: untreated MCF-7 cells. B: MCF-7 cells treated for 15 hours with ATRA 1 μM. C: time-course of ATRA effect on HEX localization. Each square represents the mean value ± standard deviation of four 100 cells counts in different slides. D: time-course of ATRA effect on HEX mRNA levels. Each dot represents the mean value ± standard deviation of three independent determinations.