IL4 and cyst: Other authors have explored the use of proteomic signatures with the landmark representative study, including a panel of MMP9, CA72.4, sFASL, and IL-4.33 Additionally, other groups have evaluated different biofluids, including saliva, serum, and urine;34,35 however, we believe that cyst fluid enables evaluation of shed IPMN cells/DNA at their source.