A "conjecture on" or a "conjecture about"?

As a non-English scientist, the question bothers me. Maybe the answer depends on the context? Allow me to give a few examples. These are titles of a short text:

  1. Is it better to say "A conjecture on the inner mechanisms of cells" or "A conjecture about the inner mechanisms of cells"?

  2. Is it better to say "A conjecture on the working of enzyme XYZ" or "A conjecture about the working of enzyme XYZ"?

  3. Is it better to say "A conjecture on the structure of DNA" or "A conjecture about the structure of DNA"?

  4. Is it better to say "A conjecture on deducing the molecular structure" or "A conjecture about deducing the molecular structure"?

  5. Is it better to say "A conjecture on the origin of chirality" or "A conjecture about the origin of chirality"?

For those who do not believe it: Google gives only a few pages of hits when searching for the two expressions ("A conjecture about": 13 pages; "A conjecture on": 7 pages). The number is so small that no conclusion can be drawn. Also there seems to be no discussion of the issue anywhere on the web.

Update: For usage statistics, look at https://books.google.com/ngrams/graph?content=a+conjecture+concerning%2Ca+conjecture+respecting%2Ca+conjecture+regarding%2Ca+conjecture+on%2Ca+conjecture+about&year_start=1800&year_end=2019&corpus=26&smoothing=3&direct_url=t1%3B%2Ca%20conjecture%20concerning%3B%2Cc0%3B.t1%3B%2Ca%20conjecture%20respecting%3B%2Cc0%3B.t1%3B%2Ca%20conjecture%20regarding%3B%2Cc0%3B.t1%3B%2Ca%20conjecture%20on%3B%2Cc0%3B.t1%3B%2Ca%20conjecture%20about%3B%2Cc0#t1%3B%2Ca%20conjecture%20concerning%3B%2Cc0%3B.t1%3B%2Ca%20conjecture%20respecting%3B%2Cc0%3B.t1%3B%2Ca%20conjecture%20regarding%3B%2Cc0%3B.t1%3B%2Ca%20conjecture%20on%3B%2Cc0%3B.t1%3B%2Ca%20conjecture%20about%3B%2Cc0


Neither seems natural English to me. If one wishes to write elegant scientific English (and “conjecture” suggests the poster might) I suggest:

“A conjecture regarding…”

A matter of taste, but I think my answer tastes better than the accepted one.