PRICKLE4, also known as over-expressed breast tumor protein (OBTP), is a member of the LIM family of proteins. It possesses two LIM domains as well as a PET domain and is thought to localize to the nucleus. Its expression in multiple malignant tissue differentiations indicate that it may play a role in cancer differentiation. Two other members of the LIM family, PRICKLE1 and PRICKLE2, are thought to function in the noncanonical WNT signaling pathway which regulates intracellular calcium release and planar cell polarity, suggesting the PRICKLE4 may play a similar role.