Whole-cell lysates of 100,000 or more cells were used per lane. Western blotting was performed as previously reported (15 (link)). Briefly, cells were rinsed with cold PBS and scraped into RIPA buffer supplemented with protease inhibitors, sonicated twice and re-suspended in 4× sample buffer (BioRad; Hercules, CA) supplemented with 10% Beta-mercaptoethanol (Sigma-Aldrich; St. Louis MO). The Pierce BCA protein assay kit (Thermo Fisher Scientific; Grand Island, NY) was used to determine protein concentration. 60 ug of protein was loaded on a 10% SDS-polyacrylamide gel and electrophoresed, and transferred to nitrocellulose (LI COR, Odyssey; Lincoln, NE) overnight at 4°C. The membrane was blocked overnight in 5% non-fat milk in TBS at 4°C. Primary antibodies used were: anti-MEIS1 (Ab19867, Abcam; Cambridge, MA), anti-MEIS2 (ARP34683_P050, Aviva Systems Biology; San Diego, CA), anti-Beta Actin, (Clone AC-15, Sigma-Aldrich; St. Louis, MO). The secondary antibodies goat anti-mouse IRDye 800 CW or donkey anti-rabbit IRDye 680 from LI-COR Biosciences were used, and images captured using an infrared Odyssey scanner (LI-COR).