PPIL4 is an evolutionarily conserved member of the cyclophilin-type PPIase family of proteins. Ubiquitously expressed with predominant expression in kidney, PPIL4 localizes to the nucleus and contains one PPIase cyclophilin-type domain, a lysine-rich domain, a pair of bipartite nuclear targeting sequences and one RRM (RNA recognition motif) domain. The presence of the RRM domain along with nuclear targeting sequences suggests that PPIL4 may be involved in transcriptional regulation.