In this task, you are given a sentence. You are expected to recognize the name of any form of chemical substances. Although there might be several correct answers, you need to write one of them.

Q: Increased responsiveness of rat colonic splanchnic afferents to 5-HT after inflammation and recovery.

A: 5-HT
****
Q: Relative expression of cholesterol transport-related proteins and inflammation markers through the induction of 7-ketosterol-mediated stress in Caco-2 cells.

A: cholesterol
****
Q: Genetic Insights into Pyralomicin Biosynthesis in Nonomuraea spiralis IMC A-0156.

A:
Pyralomicin
****