The function of SYTL1 (synaptotagmin like 1, Ensembl gene identifier ENSG00000142765) is as follows. May play a role in vesicle trafficking (By similarity). Binds phosphatidylinositol 3,4,5-trisphosphate. Acts as a RAB27A effector protein and may play a role in cytotoxic granule exocytosis in lymphocytes (By similarity). {ECO:0000250, ECO:0000269|PubMed:11278853, ECO:0000269|PubMed:18266782}.