To determine whether P/CQ treatment prevents PDAC tumor growth with or without the expression of c-MYC, mice were xenografted with Tet-On c-MYC–expressing HPAF-II or PDX220 cells (Fig. 6, A and C) and treated with (1) vehicle (control), (2) Dox to induce c-MYC expression (Dox), (3) palbociclib (P, only in PDX220), (4) P/CQ, or (5) Dox plus P/CQ (D/P/CQ). Here, MYC is linked to neoplasm.