P21 is negatively regulated, in part, by Ras and, accordingly, FTS increases p21 levels.23,29 Furthermore, p21 levels are upregulated in Gal-3 knockdown PC3 cells (human prostate cancer) along with cell cycle arrest at the G1 phase.38 Gal-3 promotes cell cycle progression by enhancing the expression of cyclin D and c-MYC.44–46 In myeloma cells, MCP induces G1 arrest and apoptosis via upregulating p21 expression.39 Our results showed that combined treatment with FTS+MCP significantly decreased p53 levels. This evidence concerns the gene TP53 and plasma cell myeloma.