Interestingly, many cancer “neoantigens” (for example, MAGEB1) are also expressed in meiotic cells in the testis. This is because they’re usually epigenetically suppressed in healthy tissues, but cancer cells have messed up epigenomes. See: https://en.wikipedia.org/wiki/Cancer/testis_antigens
Also, I would disagree that synthesizing long polypeptides is easier than synthesizing long mRNAs. With polypeptides you have 20 amino acids to work with, and some require special treatment (protecting groups on sidechains). With mRNAs the chemistry is much simpler.
I thought blackbody radiation was Planck, not Einstein.