Immunoglobulin D, an antibody protein involved in the maturation of B cells
Immunologically, peripheral B-cells show more functional IgD+ positive CD27 cells than usual.
For example, Adobe Flash programs running outside the sandbox (specific version needed with security issues) are capable of generating a specific type of HTTP request which allows a router implementing the UPnP IGD protocol to be controlled by a malicious web site when someone with a UPnP-enabled router simply visits that web site.