The results of a GWAS are sensitive information and SPOT takes several steps to ensure this information is protected during a session and is destroyed when the session is complete. SPOT uses a DigiCert encryption certificate (http://www.digicert.com) so that all communication between the user and the server are secure. Any information the user uploads is destroyed after 3 h or immediately at the user’s request. Since the results depend only on the relative order of the SNPs, the user may scale the P-values by a fixed factor prior to uploading them so that the true values are never transmitted. Nevertheless, if the user does not wish to upload P-values they may select the option ‘SNPs only, no p-values’ on the main page. In this case, SPOT provides an Excel file with the prioritization scores into which the P-values can be pasted. SPOT includes a calculated column in the Excel file that computes the weighted P-values (Pw = P/10S where S is the overall prioritization score) which are used to determine the prioritized rankings from the GIN method. This process takes place on the user’s computer so that the results are obtained without ever transferring P-values to the SPOT server.
