HOXC9 interacts with E2F6 and recruits it to cell cycle genes. (A) Reciprocal Co-IP of myc-HOXC9 and E2F6 in nuclear extracts from BE(2)-C/Tet-Off/myc-HOXC9 cells cultured in the absence of doxycycline (Doxy) for 6 days. (B) Size-exclusion chromatography analysis of complexes containing myc-HOXC9, E2F6 or MEIS2 in nuclear extracts of BE(2)-C/Tet-Off/myc-HOXC9 cells cultured in the absence of Doxy for 6 days. (C) Co-IP of myc-HOXC9 and E2F6 in pooled Superose-6 fractions 19–21. (D) ChIP-qPCR analysis showing E2F6 binding to specific promoter regions of the cell cycle genes CCNB1 and CDCA8 in BE(2)-C/Tet-Off/myc-HOXC9 cells before (Doxy+) and after (Doxy-) HOXC9 induction. Dashed lines indicate IgG control. Error bars represent SD (n = 3). Data were analyzed with unpaired, two-tailed Student’s t-test and p values are indicated.