PPP1R1B and cancer: Based on the clinical significance of DARPP-32 and t-DARPP in lung, breast, gastric and other cancers as well as their role in Akt activation and drug resistance, DARPP-32 isoforms may represent a potential therapeutic target.29 Furthermore, the cancer-specific expression profile of DARPP-32 isoforms lends itself well to safe targeting and minimal toxicity to non-malignant tissue.