PTEN and cancer: It mainly suppresses the expression of PI3K and p-Akt key target genes; downregulates the expression of Bcl-2, cyclin D1, and CDK4; and upregulates the expression of Bax, p21, and phosphatase-tensin homolog (PTEN) to reduce the viability of cancer cells, inhibit cell colony formation, induce cell apoptosis and then reverse MDR.