The heart muscle contracts and relaxes when calcium is released from a reservoir inside into the muscle cell and then pumped back quickly.

BBC: Gene link to inherited heart disease

This is fascinating to people interested in the question of how genomes switch from state to state say, from the state of a stem cell, which can grow into almost anything, to that of a muscle cell, committed to an existence of contraction and expansion.

ECONOMIST: Human genomics

Scientists have already identified the genes responsible for building muscle and increasing red cell production.

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The long-term hope is to treat patients with some sort of stem cell that could turn into beating heart muscle and replace dead cardiac tissue with fully functioning new cells.

FORBES: Using Thigh Muscle To Fix The Heart

"I need muscle relaxants, " he tells his doctor over his cell phone.

FORBES: Pressing For Change

They used stem cells from a human embryo, which are capable of becoming any other type of cell in the human body from nerve to skin, muscle to kidney.

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These cells can differentiate into many different cell lines, including cardiac, neuro, or even skeletal muscle.

CNN: Dr. Sanjay Gupta: Understanding stem cell research

Chemo-radiotherapy specifically degrades muscle mass, and depresses the function of mitochondria, the tiny structures that act as the boiler room of the cell, generating energy.

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