Hi dear Rers, I am using SSOAP package to access SOAP service at NCBI. I followed the example code in SSOAP but failed. > z <- .SOAP("http://www.ncbi.nlm.nih.gov/entrez/eutils/soap/soap_adapter.cgi", method="run_eInfo", db="pubmed", action = I("einfo")) Error: protect(): protection stack overflow what's wrong? Thanks very much. Regards