The NCI invites the submission of a request for an administrative supplement to active NCI-funded grants and cooperative agreements. The goal is to encourage new interdisciplinary collaborations between outside (non-DSRN-supported) investigators and DSRN U54-supported investigators to perform research within the scientific scope(s) of their active parent grant(s) and/or cooperative agreement award(s). These collaborations between applicants and a U54 DRSN group are expected to lead to improved pre-clinical evaluations of novel discoveries in cancer drug resistance that could ultimately be tested in NCI-sponsored clinical trials. Non-DRSN investigators can also propose to conduct collaborative studies to advance mechanistic validation of their discoveries in cancer drug resistance using the cancer drug resistance resources of the DSRN. Results from the mechanistic studies fostered through this opportunity could feasibly lead to clinical validations of concepts that identify and circumvent cancer drug resistance in patients.