PTPN1 and metabolic syndrome: By boosting STAT3 phosphorylation and reducing the expression of two important mediators of leptin resistance—suppressor of cytokine signaling 3 (SOCS3) and protein tyrosine phosphatase 1B (PTP1B)—PEA may help overcome leptin resistance, a condition commonly associated with obesity and metabolic syndrome where the body’s responsiveness to leptin is diminished.