PAK4 and cancer: More importantly, the increased expression of MHC I by PAK4 KO was not affected by the inhibition of autophagy, suggesting an autophagy-independent pathway involved in the PAK4-KO-stimulated expression of MHC I. As autophagy is a complex cellular mechanism and can play a variety of roles in cancer cell function, further investigation is required to determine the role of autophagy induced by PAK4 inhibition in PDA.