Colon cancer cells exposed to simultaneous HSP90/HSP70 inhibition demonstrated significantly decreased cell viability compared with samples without inhibitors in control cells and tumor cells pretreated with 5-FU, OXA, or MMC (control cells: 83% versus 100%, P < .05; 5-FU: 97% versus 77%, P < .005; OXA: 79% versus 66%, P < .05; MMC: 59% versus 48%, P < .05) (Figure 6E). This evidence concerns the gene HSP90AA1 and colonic neoplasm.