The former hypothesis is not supported by the presence of anti-NPM-positive/aCL-negative sera and, conversely, aCL-positive/anti-NPM-negative sera and by the demonstration that anti-NPM antibodies induced by immunization of normal mice do not react with CL (data not shown); this conclusion was also reached by Li and colleagues [17], who showed that affinity-purified anti-NPM antibodies from SLE sera did not bind to CL. Here, NPM1 is linked to systemic lupus erythematosus.