PRP4K and early-onset autosomal dominant Alzheimer disease: The current findings suggest that Loss of function of homeodomain-interacting protein kinase 2 (HIPK2) has been linked to the development of Alzheimer’s disease, and the homeodomain-interacting protein kinases (HIPKs) reside on a branch together with PRPF4B. However, PRPF4B has not yet been reported as AD-related gene70.