The present invention relates to methods for identifying compounds that can reduce
immune rejection, for example, transplant- or autoimmune disorder-related
immune rejection. The present invention is based, in part, on the discovery, demonstrated herein, that
immune rejection can be monitored by determining the amount of particular members of the Jak / Stat
signal transduction pathway present within an affected tissue. The present invention is further based, in part, on the discovery, demonstrated herein, that immune rejection can be reduced and tolerance can be induced by modulating the amount of these particular members of the Jak / Stat
signal transduction pathway present, expressed or active within an affected tissue. In particular, the results demonstrate that immune rejection can be monitored by determining the amount of mRNA or
protein of Stat1, Stat3, Stat4, Stat6, SOCS1, or SOCS3 present, e.g., in an affected tissue.