A method of treatment of cancer, viral infections, and the like administers anti-TK1 antibody, constituted as the complete antibody or a fragment thereof. The antibody binds to the surface of cells expressing TK1 thereon. The antibody, with or without another agent bound thereto, may effect complement mediated lysis, antibody-dependent cell-mediated cell cytotoxicity, apoptosis, an immune response by the mammal, a reduction in cellular replication, a combination thereof, or the like for such cells. The antibody may be coupled to an immune response stimulator, a cytotoxin, an enzyme, a combination, or the like to effect the treatment desired.