But what do you expect from an author who states that regular x-ray devices use cathode rays (aka electrons), while Nanox doesn't.

Source: https://seekingalpha.com/article/4657936-nano-x-next-few-quarters-will-be-critical-for-adoption?source=feed_all_articles

There are also some contexts in which x was chosen specifically to indicate something unknown or extra, such as when the German physicist accidentally discovered X-rays in 1895 while experimenting with cathode rays and glass.

Source: https://phys.org/news/2023-08-unknown-algebra-math-mystery.html