It might depend on what you consider "ignored". Shortly after Dolly the Sheep became famous, Ian Wilmut (one of the main people of that project) visited my uni

It might depend on what you consider "ignored". Shortly after Dolly the Sheep became famous, Ian Wilmut (one of the main people of that project) visited my university for a talk, and I asked him if he was concerned about the impact of mitochondrial differences between the genetic donor and the host egg. He was quite dismissive, saying (IIRC) "mitochondria are responsible for at most 5% phenotypical expression". To me that sounded like a lot (and I had asked the question because I expected mitochondrial differences to really matter) but he did not share my view. So, yes, if Dr. Wilmut's reaction was typical, I think it's fair to call that "ignored". Not "unknown", but ignored.