SRPX1 was initially identified as a candidate gene for X-linked retinitis pigmentosa and is overexpressed in the trabecular network of the eye in glaucoma conditions. Its expression is significantly downregulated in a number cancer cell lines and malignant tumor tissues and its ectopic expression induces apoptosis through the endoplasmic reticulum and the activation of caspase-12, -9, and -3, indicating that it can function as a tumor suppressor. SRPX1 is also involved with the regulation of autophagy under low serum conditions and can associate with Rab24, a member of the Rab GTPase protein family that is involved in autophagy. This association of SRPX1 with Rab24 is enhanced during autophagy.
