Methods and compositions for targeting proteins to secretory lysosomes.

Entity fusion secretory lysosome targeting mast cell, basophil, hemopoietic cell, melanocyte or goblet cell comprising: (a) a polypeptide that specifically localizes to a secretory lysosome and is released with the granule content into the extracellular milieu after stimulation and cell degranulation and (b) a fluorescent label polypeptide.