DGK activity in NIH-EGFR/ALK cells following EGF stimulation. NIH-EGFR/ALK cells were serum-starved for 18 hours and then either mock-treated or treated with 100 ng/mL EGF for the indicated time at 37°C. (A) Cell lysates were analyzed for in vitro DGK enzymatic activity as described in Figure 1. (B) PA spots were quantified by densitometric scanning of the autoradiograms and results are expressed as percent of control (signal obtained from medium-treated cells). Results are representative of 3 independent experiments.