Diagnosis and prognosis of various types of cancers

1. A method of classifying a liver cancer as hepatocellular carcinoma (HCC) or liver metastasis, the method comprising: (a) providing RNA isolated from a liver sample obtained from a human subject having a liver cancer; (b) detecting in said RNA an expression level of SEQ ID NO: 42 with a nucleic acid probe consisting of a sequence complementary to SEQ ID NO: 42 and a linker of 20-27 nucleotides at the 3′ end of said complementary sequence; wherein said probe is attached to a solid substrate; and wherein said expression level is normalized; (c) comparing the normalized expression level of SEQ ID NO: 42 to a reference value, wherein said reference value comprises: (i) mean normalized expression levels of SEQ ID NO: 42 in human liver cancers diagnosed as HCC, wherein increased expression of SEQ ID NO: 42 in the liver sample as compared to the reference value is indicative of liver metastasis; or (ii) mean normalized expression levels of SEQ ID NO: 42 in human liver cancers diagnosed as liver metastasis, wherein decreased expression of SEQ ID NO: 42 in the liver sample as compared to the reference value is indicative of HCC; and (d) classifying said human subject's liver cancer as HCC or liver metastasis based on said comparison.

2. The method of claim 1 , wherein said liver sample is a fresh, frozen, fixed, wax-embedded or formalin fixed paraffin-embedded (FFPE) tissue.

3. The method of claim 1 , wherein the expression levels are detected by a method selected from the group consisting of nucleic acid hybridization and nucleic acid amplification.

4. The method of claim 3 , wherein the nucleic acid hybridization is performed using a solid-phase nucleic acid biochip array.

5. The method of claim 1 , wherein the probe is attached to the solid substrate by an amine group.