<prompt> Perforins are produced by:Cytotoxic T cellsSuppressor T cellsMemory helper T cellsPlasma cells  <response>: Perforins are hole forming proteins synthesized by cytotoxic T-cells. They can perforate the plasma membrane of the target cells that are under attack by CD8 lymphocytes. Granzymes are delivered into the target cells through these holes formed by perforins. In addition, the perforin pores allow water to enter the cells, thus causing osmotic lysis. 