The present invention relates to transgenic animals, as well as compositions and methods relating to the characterization of gene function. Specifically, the present invention provides transgenic mice comprising disruptions in PRO226, PRO257, PRO268, PRO290, PRO36006, PRO363, PRO365, PRO382, PRO444, PRO705, PRO1071, PRO1125, PRO1134, PRO1155, PRO1281, PRO1343, PRO1379, PRO1380, PRO1387, PRO1419, PRO1433, PRO1474, PRO1550, PRO1571, PRO1572, PRO1759, PRO1904, PRO35193, PRO4341, PRO4348, PRO4369, PRO4381, PRO4407, PRO4425, PRO4985, PRO4989, PRO5737, PRO5800, PRO5993, PRO6017, PRO7174, PRO9744, PRO9821, PRO9852, PRO9873, PRO10196, PRO34778, PRO20233, PRO21956, PRO57290, PRO38465, PRO38683 or PRO85161 genes. Such in vivo studies and characterizations may provide valuable identification and discovery of therapeutics and/or treatments useful in the prevention, amelioration or correction of diseases or dysfunctions associated with gene disruptions such as neurological disorders; cardiovascular, endothelial or angiogenic disorders; eye abnormalities; immunological disorders; oncological disorders; bone metabolic abnormalities or disorders; lipid metabolic disorders; or developmental abnormalities.