SZL P1-41, a skp2 inhibitor, can prevent assembly of Skp2-Skp1 complexes. It selectively suppresses Skp2 SCF E3 ligase activity but exhibits no effect on the activity of other SCF complexes. It also inhibits Skp2-mediated p27 and Akt ubiquitination in vivo and in vitro. It suppresses the survival of Y cells and Y stem cells by triggering cell senescence and inhibiting glycolysis. It exhibits antitumor effects in multiple animal models and Y cell lines.