The fact that exposure of MIA PaCa-2 cells to higher concentrations of LIF (25, 50, and 100 ng/mL) promoted a reduction of cell vitality is consistent with the finding that, in some systems, this cytokine exerts direct cytotoxic effects (Figure 2D) as reported by us and others in gastric cancer cell lines [16,42]. This evidence concerns the gene LIF and gastric cancer.