Immunoglobulin M heavy chain (IGHM) fragment [Homo sapiens] is a fragment (Gly-Val-Ala-Leu-His-Arg-Pro-Asp-Val-Tyr-Leu-Leu-Pro-Pro-Ala-Arg) on the human immunoglobulin micro heavy chain. Immunoglobulins (Ig) are the antigen recognition molecules of B cells. An Ig molecule is made up of 2 identical heavy chains and 2 identical light chains joined by disulfide bonds so that each heavy chain is linked to a light chain and the 2 heavy chains are linked together. Each Ig heavy chain has an N-terminal variable (V) region containing the antigen-binding site and a C-terminal constant (C) region, encoded by an individual C region gene, that determines the isotype of the antibody and provides effector or signaling functions.