SEPTIN9 and colonic neoplasm: In contrast to the increased proliferation observed in SEPT9-KO intestinal epithelia in vivo (Supplemental Figure 3, B and C), SEPT9 KO in HT-29 cells did not affect IEC proliferation (Supplemental Figure 6, D and E), potentially reflecting intrinsic differences between normal IECs and this colon cancer–derived cell line.