While protein tyrosine phosphatase 1B acts as a gatekeeper molecule at the confluence of multiple signal transduction pathways, the enzyme so far has been targeted only for Type II diabetes and obesity. A paper published last week in Nature Genetics revealed another role for PTP-1B inhibitors, this time in suppressing HER2-positive breast cancer growth and metastasis.

PTP-1B inhibition has been shown to increase insulin sensitivity and improve glucose tolerance by preventing the enzyme from dephosphorylating the insulin receptor kinase. Based on that activity, several companies have PTP-1B inhibitors in development for diabetes and obesity.