Exciting - exercise makes your muscles produce substances that fight cancer....

This is exciting.  A mechanism of how exercise really is good for you in fighting cancer

A novel myokine, secreted protein acidic and rich in cysteine (SPARC), suppresses colon tumorigenesis via regular exercise

Conclusions These findings suggest that exercise stimulates SPARC secretion from muscle tissues and that SPARC inhibits colon tumorigenesis by increasing apoptosis