It's the article title and a key topic in the article.

"Also in 2011, some researchers figured out how to reengineer H5N1—avian influenza virus—to make it much scarier by causing five mutations at the same time that all together made the virus both easy to spread and quite lethal"

I'm not blaming the HN submitter, I'm blaming the author of the blog post. It's not just a key topic, it's the subject. You can't title a programming article "Programming", it has to be about something. Unless you're going for clickbait, which seems to work.