Comments: This is a really interesting online tool. Apart from the annotation features that it has , it also features comparison between the different datasets that one can store therein. The supported identifiers include GenBank Accession Numbers, UniGene Cluster ID, IMAGE Clone ID, University of Iowa clones, Agilent Oligo ID, Operon Oligo and Affymetrix ID. Concerning the comparison between the different sets the following choices are available quoting from the site 1) Master-Target test: One of the two lists of genes compared is the list containing all genes present in the full experiment. This list is called the Master list, e.g. all genes assayed on the chip in a microarray experiment where inference was possible. The test is performed using Fisher's exact test. 2) Mutually Exclusive Target-Target test: Two gene lists, A and B, are compared, and there are no genes that are on both lists, e.g. A is a list of genes associated with up-regulation and B is a list of genes associated with down-regulation. This question can be translated into testing if two independent binomial proportions are equal. The test is performed using Fisher's exact test. 3) Intersecting Target-Target Situation: Two gene lists, A and B, are compared, and there exist genes that are on both lists, e.g. A is a list of genes associated with treatment A, and B is a list of genes associated with treatment B and there exist genes that have responded to both treatments. Based on a generalized linear model and generalized estimation equations Leisering, Alonzo and Pepe (Biometrics, 2000) defined a test statistic for comparing positive predictive values for diagnostic test for large samples. We have translated their test into the situation of two intersecting gene lists. |