License Information

Data

The serotype assignments, serotype definitions and every API response and bulk file derived from them come from the HLA Allele To Serotype (HATS) pipeline of Osoegawa et al., © 2022 Stanford Blood Center L.L.C. The HLA Serotype Database redistributes these data under the same BSD 3-Clause license, reproduced below. You may use, copy and redistribute them, with or without modification, provided the copyright notice, the conditions and the disclaimer are kept with them.

© 2022 Stanford Blood Center L.L.C.

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

    Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.

    Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.

    Neither the name of the copyright holder nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

Please cite the HATS classification when you use the data:

Osoegawa K, Marsh SGE, Holdsworth R, et al. A new strategy for systematically classifying HLA alleles into serological specificities. HLA. 2022;100(3):193-231. doi:10.1111/tan.14662

We also ask that you cite the HLA Serotype Database in any publication or project that makes use of this resource:

[Publication Placeholder] when using this resource

cPRA reference data

The cPRA calculator uses the NMDP five-locus HLA haplotype frequencies for US populations (December 2007 release; Maiers M, Gragert L, Klitz W. Hum Immunol. 2007;68(9):779-788) and the OPTN deceased-donor population proportions as reference data. They are used on this site to compute results and are not redistributed: the downloads include each serotype's computed cPRA contribution, not the frequency tables.

Using this website and API

The website, its analysis tools, the GraphQL API and the bulk downloads are free of charge. The API requires a free account and key, used only to monitor usage and prevent abuse. Use of the site and the API is governed by our Terms of Use: the site and its data are provided for research and educational use, not for clinical decision making, and no protected health information may be sent to the API.

R example code

The R lessons on the API page are distributed under the MIT License, so you may copy, adapt and redistribute them freely as long as the notice below stays with them.

MIT License

Copyright (c) 2026 HLA Serotype Database Project

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.

Source code

The source code of the website and API is not publicly distributed. If you have questions about licensing or usage permissions, please contact us .