In higher (multicellular) organisms, many processes are required for coordinating individual cells to act as parts of the whole. Among these we may count attraction of spermatozoides by ovum, environment sensing in general, cellular response to hormones and neuro transmitters, initiating and terminating cells multiplication, or imposing apoptosis on unneeded cells during ontogenesis.

Usually, Signal-Transduction would begin with binding of the singnal-molecule to a receptor on the cell-membrane, altering its configuration and thus starting a chain of reactions within the cell. These reactions may include (de)acetylations, (de)/phosphorilations on the participating molcules.

The Signal Transduction related reagents may by further classified as

• Ca⁺⁺-ATPase inhibitors, such as Artemisinin, Cyclopiazonic acid, Thapsigargin, Paxilline
• SERCA Ca²⁺-ATPase stimulator/ activator, such as Ochratoxin A
• Hedgehog signalling inhibitors: Cyclopamine