PAK2 and Immunodeficiency: Among the pathways, the signaling by receptor tyrosine kinases (PAK2; p = 2.69e–20), T-cell receptor signaling (PAK2-PLCL1; p = 5.37e–10), GABA and human immunodeficiency pathways (PAK2-TAP2; p = 1.13e–06) are significantly enriched (Figure 3A).