Erythropoiesis is considered to be the result of a series of molecular events which alter gene expression. Recently, advances have been made in the understanding of several aspects of erythroid gene expression. A variety of transcription factors are now known to control expression of specific genes in the nucleus. Some of these are influenced by action of cytokines at the cell surface, an example of which is the interaction of c-kit with its ligand, the stem cell factor. Abnormalities in the regulation of transcription factor genes are implicated in leukemogenesis. Furthermore, an additional level of complexity in gene expression is provided post-transcriptionally, by which alternative splicing of RNA transcripts result in erythroid-specific proteins. In this way, changes in gene expression in erythroid progenitor cells directly contribute to the formation of the mature erythrocyte.