H5N6 is one of the six main hemagglutinin (HA) subtypes of bird flu viruses to have infected people and cause acute respiratory illness.

Source: https://www.dailymail.co.uk/health/article-11812571/China-reports-TWO-human-cases-bird-flu-middle-aged-man-woman-hundreds-miles-apart.html?ns_mchannel=rss&ns_campaign=1490&ito=1490

The new study identified more than 70 different gene subtypes, based on subtle differences, that are located either at NOR2 or NOR4, but not both.

Source: https://phys.org/news/2023-12-gaps-arabidopsis-genome-sequence.html

There are several subtypes of depression.

Source: https://www.cnet.com/health/mental/top-signs-you-might-have-depression-and-how-to-get-help/