PACE4 is a member of the mammalian propeptidase family that has overlapping but not identical substrate specificity to PACE.
Rehemtulla A, Barr PJ, Rhodes CJ, Kaufman RJ. PACE4 is a member of the mammalian propeptidase family that has overlapping but not identical substrate specificity to PACE. Biochemistry. 1993 Nov 02; 32(43):11586-90.