Furthermore, the expression of GCSF and GCSFR is increased in several types of solid tumors including breast cancer, bladder cancer, GI cancers, and gliomas (8, 49–51). While GCSFR regulation has primarily been studied in myeloid cells, here we will discuss what is also known about GCSFR regulation in both myeloid and non-myeloid cells. This evidence concerns the gene CSF3 and central nervous system cancer.