V24J18

V24J18 is a designation used in immunology literature to denote a hypothetical rearranged immunoglobulin variable region, formed by the pairing of a variable (V) gene segment labeled "V24" with a joining (J) segment labeled "J18". In the human genome, immunoglobulin genes are organized into V, D, and J segments that recombine to create diverse antibodies. While actual human V and J segments carry more detailed locus names, V24J18 is commonly used in educational materials and computational simulations as a representative example of V–J recombination.

It is used to illustrate the process of somatic recombination in B cells, as well as to discuss the combinatorial diversity generated by different V and J pairings. Sequences and descriptions of V24J18 in databases are usually synthetic or anonymized to avoid implying a real genomic locus; when present, they serve as placeholders rather than verified alleles.

Outside immunology, the code V24J18 has appeared in unrelated contexts, including as a model number for laboratory equipment, or as a fictional designation in science fiction. Its meaning is highly context-dependent and should be clarified when encountered in texts or datasets.