PRF1 and neoplasm: Several pertinent studies have validated that gangliosides, specifically GD1a, present on the surface of tumor cells, can impede the transportation and exocytosis of cytoplasmic particles in CTL (37, 38), Consequently, this inhibition impedes the perforin, granzyme, and other contents of cytoplasmic particles from executing their function on target cells, thereby hindering the mediation of target cell death.