FKBP5 and central nervous system cancer: In glioma cell lines, co-immunoprecipitation assays of proteins extracted by endoplasmic reticulum showed an interaction between FKBP51s and PD-L1.22 Moreover, FKBP51s isomerase activity was found essential to assist in glycosylation and expression on the plasma membrane of this immune-inhibitory molecule.22 Although few, these evidences suggest that FKBP51s can be better suited than FKBP51 to an immune-tolerant phenotype.