Human studies suggest expression of CD32C could help predict patient responses to vaccines. CD32C normally contains a termination codon, but 7%–15% of individuals carry a mutation that changes it into a full-length open reading frame. Individuals with this variant expressed CD32C on B cells were more likely to respond to an anthrax vaccine than patients that did not express the variant. Individuals with the full-length CD32C variant also were more likely to develop the autoimmune disease systemic lupus erythematosus (SLE) than those without the variant.