Understanding the mutational signature of SPINK1 will improve the development and management of the step-up approach for cancer patients, specifically those harboring aberrant SPINK1. Recently, a novel technique, the immunocapture-liquid chromatography-mass spectrometry (IC-LC-MS) assay, was validated as able to detect and quantify serum SPINK1, including mutant forms N34S (SPINK1) and P55S (SPINK1) [16]. This evidence concerns the gene SPINK1 and cancer.