PLCγ2, but not PI3Kγ, is required for p38 MAPK phosphorylation. Bone marrow–derived neutrophils from Plcg2^−/− mice or Pik3cg^−/− mice were plated on uncoated (unstimulated) or E-selectin–coated wells for 10 minutes, and then lysates were prepared (A-B). Lysates were immunoblotted with antibody to phosphorylated p38 MAPK (phospho-p38) or total p38 (n = 3).