CD44 and cancer: Since expressions of the KRAS/MMP7/CD44 oncogenes were demonstrated to promote distant metastasis and drug resistance in CRC [16,69], we further determined their responses to FDA-approved drugs when overexpressed in all cancers at the mRNA level, and results showed that when KRAS was elevated, it caused resistance to docetaxel, a chemotherapeutic drug [49], and to RDEA119 and selumetinib, which are both MEK inhibitors [50,51] (Figure 2A).