Research into stem cells started in the 1960s with experiments on spleen cultures. Evans and Kaufman made a breakthrough in mouse embryo culturing and embryonic stem cell extraction in 1981, followed by the work of Thomson in 1998 on the technique for extracting human embryonic stem cells. Since then, stem cell research has rapidly expanded as a therapeutic avenue for different diseases in humans. This book explains the basic developmental biology of stem cells including the development of stem cells during the implantation stage in utero to the regulation of stem cell division. Medical applications of stem cells in the therapy of diseases such as cancer, neurodegenerative diseases, and bone diseases are also explained in subsequent chapters. The book also explains the effect of parasitic cells on stem cell growth. Concepts in the book are explained in a simple clear manner, making this book an informative reference for non-experts, students and professionals in the field of biology and medicine.