S100A16 and cancer: S100A16 is a calcium-binding protein which acts as an intracellular calcium sensor and been reported as a potential biomarker in a variety of cancer types as well as reported to influence a variety of molecular mechanisms that promote tumor metastasis [13–15].To further confirm the differential nucleolar localization of S100A16, nucleolar fractions from both primary and metastatic cell line pairs were queried for S100A16 protein expression.