Inhibition of GSK3 by 9-ING-41 leads to mitotic prophase arrest. (A) Cartoon depiction of the sequential steps (M1-M5) during mitosis (purchased from Shutterstock and modified). (B) Representative images of Wright’s stained Jeko cells that were left untreated or treated with 1.0 μM 9-ING-41 for 24 hours. Various mitotic stage cells (M1-M5) are readily identified in untreated cells (left panel), whereas large numbers of only prophase cells (M1) are seen in 9-ING-41–treated cells (right panel); original magnification ×600. (C) Bar chart showing the number of mitotic M1 to M5 cells identified when 100 untreated or 9-ING-41–treated Jeko cells were counted. Similar results (data not shown) were observed in ≥4 lymphoma cell lines.