PTPN1 and colon carcinoma: Of the new cembranoids, only sinulin D (133) had mild inhibitory activity against PTP1B (protein tyrosine phosphatase 1B), nevertheless the known cembranoid 5-episinuleptolide (123) (Figure 12) showed activity against HeLa (human cervical epitheloid carcinoma) and HCT-116 (human colon carcinoma) cell lines [43].