Heterogeneity among Lgr5-positive colon stem cells.

Leucine-rich repeat-containing G-protein coupled receptor 5 (Lgr5) is considered a representative marker of intestinal stem cells from both non-tumor and tumor tissues. However, it remains unclear whether all or only a fraction of Lgr5-positive cells behave as stem cells. Recently, we reported that Lgr5-positive cells from non-tumor and tumor tissues can be classified into overlapping yet distinct groups and that the tumor-specific groups are associated with tumorigenic capability, suggesting that these cells could represent targets for therapeutic intervention.