MEIS1 and neoplasm: However, in keeping with a requirement for HOXB13 expression with MEIS1 to enact a tumor suppressive effect, ectopic expression of LV-MEIS1 in LAPC4-HOXB13ko cells significantly increased proliferation compared to HOXB13ko (p<0.05 vs. HOXB13ko, Figure 3C), rather than further decreasing proliferation or remaining growth suppressed when HOXB13 was present.