A method for determining the presence of cancer cells in a tissue sample or cell sample by detecting the presence of phosphorylated p68 RNA helicase in the sample. Further, a method for determining the presence of metastatic cancer cells in a tissue sample or cell sample by detecting the level of phosphorylated P68 RNA helicase in the sample such that a greater level of the phosphorylated protein in the sample as compared to non-metastatic cells is an indication of the metastatic cancer cells in the sample.