[5][6] This gene encodes a protein containing two conserved tandem RNA recognition motifs and functions as an RNA binding protein that is involved in post-transcriptional gene editing.

It is a stem cell marker that controls the balance between self-renewal and terminal differentiation.

[7][6] Over expression of this gene is associated with the grade of the malignancy and proliferative activity in gliomas and melanomas.

[7] An increased expression of MSI1 protein is observed in endometriosis and endometrial carcinoma[8] siRNA-mediated inhibition of MSI expression in endometrial carcinoma cells induces apoptosis and inhibits cell proliferation by affecting the Notch signaling pathway[9] MSI1 is highly expressed in neural progenitor cells and is required for normal development of the brain.

A mutation in these gene is responsible for autosomal recessive primary microcephaly.