SLC19A1 and cancer: Plasma-induced disruption of the antioxidant defense system of cancer cells by cystine uptake via xC− antiporter has been widely studied, while folate uptake by cancer cells via high expression of hSLC19A1, which generates Nicotinamide Adenine Dinucleotide Phosphate (NADPH) via one-carbon metabolism, is also an important component of the antioxidant defense mechanism of cancer cells.