Hello, I am looking at the bioconductor annotation package for hgu133plus2. I noticed that about 28 % of probesets do not have a MAP location listed for them. Could someone please point me to an updated or a developmental package that has missing MAP information. I called Affymetrix and they pointed me to their annotation csv file that has missing locations for 29 % of the probesets. Thank you for your help. Srikanth Jammulapati Bioinformatics Analyst Myriad Genetics, Inc.