SHP1 induced G₁cell cycle arrest and a decrease in the number of viable cells. Cell cycle analysis for SU-DHL1 cells transfected with pIRES2-EGFP and pIRES2-EGFP-SHP1. Cells were harvested 24 hours after gene transfection and subjected for cell sorting based on GFP expression. All GFP⁺ cells were then subjected to cell cycle analysis. SHP1 induced a significant increase in the G_0/1 population, indicating cell cycle arrest.