PTP1B Inhibitor Reduces HER2-Positive Tumors, Metastases (image) Cold Spring Harbor Laboratory Caption The candidate drug MSI-1436 (trodusquemine) inhibits HER2-positive tumor formation and metastasis through its inhibition of the enzyme PTP1B. Here, its effect on HER2-positive lung metastasis is shown: image at far left is untreated; dark areas are tumor metastases. The drug at two doses is shown to clear the metastatic lesions (dosage in center image is half that in right image). Credit Tonks lab/Cold Spring Harbor Laboratory Usage Restrictions give credit please Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.