AFP and hepatocellular carcinoma: Also, 1H-NMR plasma profiles using OPLS-DA, in which red area denoted HCC patients with normal AFP levels (less than 15 ng/mL) while green area denoted HCC patients with abnormal AFP levels (greater or equal to 15 ng/mL), have shown a separation between the patients with normal (< 15 ng/mL) and elevated AFP (≥ 15 ng/mL).