PAK1 and neoplasm: PAK1 and PAK4 double knockout (PAK1&4KO) suppressed pancreatic tumour volume (Figure 5a) in a SCID mouse model, but not tumour weight (Figure 5b,c), suggesting that PAK4KO-induced increased tumour weight (Figure 3b) compromised PAK1KO-reduced tumour weight (Figure 1b).