T cells attacking cancer cell, coloured scanning electron micrograph (SEM). The T cells (red) are attacking an oral squamous cancer cell (white). The cytotoxic (cell-killing) T cells are part of a natural immune response. Research being carried out in the field of nanomedicine is creating personalized cancer vaccines by loading neoantigens from a patient's tumour into nanoparticles. These nanoparticles are then used to activate the patient's own immune system, triggering the actions of T cells as seen here.