Disclosed are a method for detecting liver cancer capable of detecting livercancer with high specificity and a diagnostic therefor, as well as a noveltherapeuticdrug for cancer having an excellent anticancer effect. The method fordetectingliver cancer cells in a sample utilizes as an index the expression of dlkgene. Theexpression of dlk gene may be measured by immunoassay using an anti-dlkantibodyor by measuring mRNA of dlk gene. The therapeutic drug for cancer comprises asan effective ingredient an antibody which undergoes antigen-antibody reactionwithDlk expressing on surfaces of cancer cells and which exerts anticancer actionagainstthe cancer cells.
