Inhibition or loss of PTP4A3 did not alter 2D growth but decreased colony formation. A) Growth rate of PTP4A3fl/fl and PTP4A3−/− cells grown as monolayer on plastic (n = 6). Error bars indicate sem. B) PTP4A3−/− cells displayed a marked decrease in colony formation when grown in soft agar compared with PTP4A3fl/fl cells. Representative images of cells stained with crystal violet seen below graph (n = 3). Error bars indicate sem. ***P < 0.001. C) Concentration-dependent reduction in anchorage-independent colony formation of PTP4A3fl/fl cells, but not PTP4A3−/− cells, after exposure to JMS-053 (n = 3). Error bars indicate sem. N.S., not significant. *P < 0.02, **P < 0.0005, ***P < 0.0001 (determined by 2-way ANOVA).