SLC16A1 and colorectal cancer: Interestingly, this mechanism is also observed in cancer cells where it is known as “metabolic symbiosis.” Sonveaux et al. (53) found that cervical cancer-derived SiHa cells, which expressed higher levels of MCT1 but lower levels of MCT4, consumed significantly more lactate and less glucose than colorectal cancer WiDr cells, conversely, WiDr cells, which expressed higher levels of MCT4 and lower levels of MCT1, consumed less lactate and more glucose than SiHa cells.