Identification of tumors

A method of classifying a cell-containing sample obtained from a subject as containing tumor cells of a type of tissue, said method comprising

• selecting randomly 50 or more transcribed sequences of the subject;
• producing cDNA copies of the 50 or more randomly selected transcribed sequences from cells in the cell-containing sample;
• amplifying the cDNA copies to produce amplified molecules;
• determining expression levels of the 50 or more transcribed sequences;
• comparing the determined expression levels to expression levels of the same 50 or more transcribed sequences in a plurality of known tumor types comprising one or more tumor types selected from the group consisting of testicular germ cell, sarcoma, adrenal gland, brain, breast, carcinoid-intestine, cervix-adenocarcinoma, cervix-squamous, endometrium, gall bladder, germ cell-ovary, GIST (gastrointestinal stromal tumor), kidney, liver, lung-adenocarcinoma-large cell, lung-small cell, lung-squamous, lymphoma-B cell, lymphoma-Hodgkin's, lymphoma-T cell, meningioma, mesothelioma, ovary-clear cell, ovary-serous, pancreas, prostate, skin-basal cell, skin-melanoma, skin-squamous, small and large bowel, soft tissue-MFH (malignant fibrous histiocytoma), stomach-adenocarcinoma, thyroid-follicular-papillary, thyroid-medullary, and urinary bladder, and
• classifying the sample as containing or not containing tumor cells of a tumor type or tissue in the plurality of known tumor types.