PAK1 and gastric cancer: Using a mRFP-GFP-LC3 double fluorescent autophagy indicator system transfection and Western blot rescue experimentation, we discovered that PAK1 overexpression could only partially alleviate the increase in autophagosomes and autophagic lysosomes, the reduction in P62 expression, and the increase in LC3-II expression in GC cells after circPTPN22 knockdown (Fig. 6A, B, and I).