CASP3 and neoplasm: Therefore, monitoring the activity of caspase-3/7 could be used for evaluating tumor response to therapy, such as chemotherapy [38], photothermal therapy (PTT) [39], radiotherapy [40], etc. Together with the aforementioned enzymes, a variety of enzymes have been exploited as potential triggers for activatable fluorescent probes, such as granzyme B [41,42,43,44], matrix metalloproteinases (MMPs) [45,46,47], and aminopeptidase N [48,49].