PRF1 and infection: Many Gram-positive and Gram-negative bacteria, produce hemolysins/cytolysins that are powerful virulence factors which lyse and kill host immune cells.100–102 These virulence factors not only contribute to the survival of the pathogens by providing access to nutrients but also weaken the immune system of the host.103–105 These hemolysins/cytolysins may be used by opportunistic pathogens to develop system infections in the host.