Final answer:
Cytotoxicity is primarily associated with T lymphocytes, specifically cytotoxic T cells, which target and kill virus-infected or cancerous cells in a specific manner, differing from the generalized response of natural killer (NK) cells.
Step-by-step explanation:
Cytotoxicity, which refers to the ability of certain lymphocytes to kill specific target cells, is primarily associated with T lymphocytes, especially the cytotoxic T cells. These cells play a crucial role in the cell-mediated immune response by destroying cells that have been infected with viruses, as well as other cells that have become cancerous or display abnormal characteristics. While natural killer (NK) cells also possess cytotoxic capabilities and are part of the innate immune response, they target and kill infected or abnormal cells in a non-specific manner, unlike the specific targeting of cytotoxic T cells.