MurA-IN-1 (compound 1a) is a PTPRR inhibitor, with IC50 values of 0.23 μM, 0.8 μM, 0.75 μM and 0.09 μM for PTP1B, PTPN5, PTPN7 and PTPRR, respectively[1]. (A family of human MAPK-specific protein tyrosine phosphatases) [1]. Jeyanthy Eswaran, et al. Crystal structures and inhibitor identification for PTPN5, PTPRR and PTPN7: a family of human MAPK-specific protein tyrosine phosphatases. Biochem J. 2006 May 1;395(3):483-91.