In this task, you are given a sentence. You are expected to write the name of the organism substances in the body mentioned in the input. Although there might be several correct answers, you need to write one of them.

Q:  On the contrary , the administration of 5 - CT induces a rise in IOP , which is partly or entirely caused by an increase in aqueous humor secretion mediated by 5 - HT7 receptors [ 84 ] .

A: humor
****
Q:  No blood flow signal was observed in the masses of 13 cases ( 3 of metastatic adenocarcinoma , 5 of adenoma , 5 of polypus ) .

A: blood
****
Q:  The goal of this study was to determine whether immunosuppression plays a role in the level and duration of fecal shedding of Escherichia coli O157 .

A:
fecal
****