Histamine and PAR-2-induced hyper scratching in PI3Kγ deficient mice. (A and B) The total number of scratches that occurred over a 40-minute time period after histamine injection were counted. PI3Kγ KO exhibited enhanced scratching compared to WT littermates. (C and D) PAR-2 agonist induced itch was recorded; scratches were counted for 30 minutes. (E and F) The PI3Kγ KO scratched vigorously for the first 5 minutes; the latency until the first scratch was significantly earlier than in WT mice.