Phosphatase of regenerating liver (PRL) phosphatases (protein tyrosine phosphatases (PTP4A1–3)) were first identified in the regenerating liver and subsequently found to be upregulated in cancer.1,2 The majority of studies have identified an involvement of the Akt–phosphatase and tensin homologue (PTEN) pathway, but no consensus has emerged for their substrates or downstream effectors. The gene discussed is PTEN; the disease is cancer.