Our own-developed mouse model of Pten conditional knockout (Pten-CKO) can be mated with mice carrying tissue-specific Cre expression to obtain mice with homozygous deletion of Pten in specific tissues or cells, thus avoiding the embryonic death caused by systemic and homozygous Pten knockout. Pten-CKO mice can be used to study tumorigenesis, anti-tumor targets, neurogenesis, glial differentiation and cerebellar development.