IgD is only expressed in association with [[IgM]]. It is thought to be important in B-cell development, although it has been shown in δ chain knockout mice (so they have no functional IgD) do not have any noticeable defects in immune function. | IgD is only expressed in association with [[IgM]]. It is thought to be important in B-cell development, although it has been shown in δ chain knockout mice (so they have no functional IgD) do not have any noticeable defects in immune function. |