ABT-199 sensitivity in a mouse xenograft model of the T-ALL cell line LOUCY. Thirteen mice xenografted with luciferase positive LOUCY cells were vehicle treated or ABT-199 treated (100 mg/kg body weight) for 4 days. The bioluminescence was measured before the start of the treatment (day 0) and after 2 and 4 days of treatment. Each column with pictures represents 1 individual mouse. The total bioluminescence signal after 4 days of treatment is plotted relative to the start value at day 0 for each mouse.