The present study aimed to address three key questions essential for a deeper understanding of the pharmacological potential of Sol-DMAP: (i) whether it enhances the antitumor efficacy of DOX in a P-gp–overexpressing RLS40 lymphosarcoma murine model, (ii) whether this triterpenoid possesses its own antitumor activity in vivo, and (iii) whether it exerts a protective effect against DOX-induced hepatic toxicity in experimental mice. This evidence concerns the gene PGP and lymphoma.