MMP9 and neoplasm: Based on a variety of quantitative and qualitative factors, including increased MMP-9 secretion, increased invasiveness, overexpression of S100P, increased colony formation, and morphological changes, exposing HPDE cells to cadmium for 29 weeks caused acquisition of multiple tumor cell characteristics and these are henceforth designated CCE (chronic cadmium exposed) cells to reflect this distinction from control cells.