What characters are believed to be mutants but never confirmed in print?

[Lonewolf36]

Asp (Cleopatra Nefertiti)
She has been speculated as being a mutant for years.

Chat (Sophia Sanduval)
Her Earth-20051 counterpart is a mutant but she has shown no powers in her few appearances.

Death Reaper
The daughter of Nekra Sinclair is a possible mutant with Darkforce controling powers that also posseses mystical abilities.

Profile
A Moon Knight villain that has been speculated to be a mutant.

Proton (Geldoff)
His Earth-1610 counterpart has the same abilities an is a confirmed mutant.

Radiance (Ryoko Sabuki)
Her deceased sister Goldfire had the same abilities and was confirmed a mutant.

Tangerine
Her Earth-811 counterpart is a confirmed mutant.

Voice (Jason Cragg)
Has been stated to possibly be a latent mutant whose powers were activated by ionized atoms.

[Drexelhand]

I've heard people speculate the original Madame Webb was a mutant.

[Wiccan]

Wiccan and Speed. I don't think Marvel's editorial considers them mutants, but they were called so back in the day. I think the assumption on Marvel was that the Axis retcon counts for them too or something.

[ExodusCloak]

Wiccan and Speed. I don't think Marvel's editorial considers them mutants, but they were called so back in the day. I think the assumption on Marvel was that the Axis retcon counts for them too or something.

Were they not offered sanctuary by Magneto in Gillens run and in Children's Crusade by Emma

Cloak and Dagger

[Huntsman Spider]

Were they not offered sanctuary by Magneto in Gillens run and in Children's Crusade by Emma

Cloak and Dagger

Yeah, Cloak and Dagger keep going back and forth on whether or not they're mutants whose powers were awakened by the experimentation they went through, or the experiments themselves were what gave them their powers.

[danielsan52]

Sara Grey. Attuma stated she was a mutant. If she is , she should be resurrected along with her twin mutant children.

[danielsan52]

I thought for sure Nia Noble was but now I’m not so sure. http://www.marvunapp.com/Appendix3/nobleniainv.htm

[Chris0013]

Cloak and Dagger

Yeah, Cloak and Dagger keep going back and forth on whether or not they're mutants whose powers were awakened by the experimentation they went through, or the experiments themselves were what gave them their powers.

They were tested after the whole Osborn's Dark X-Men thing....Doctor Nemesis said they did not test positive for the x-gene.

I believe it was this issue. https://marvel.fandom.com/wiki/Cloak_and_Dagger_Vol_4_1

[Huntsman Spider]

I've heard people speculate the original Madame Webb was a mutant.

Yeah, that might've been the case, as she wasn't bitten by a mutated or modified spider, or exposed to spider DNA in some other way, to gain her powers of clairvoyance, precognition, and telepathy that connected her to the Web of Life and Destiny that was the ultimate source of all spider-powered individuals.

[Loki]

Tangerine
Her Earth-811 counterpart is a confirmed mutant.

When was she confirmed to be a mutant?

[Lonewolf36]

When was she confirmed to be a mutant?

I may be confused on this one and could be thinking of someone else entirely.

[Loki]

I may be confused on this one and could be thinking of someone else entirely.

It's not mentioned as far as I can see in her two issues appearance in Excalibur, and it seems likely she wasn't for one simple reason - she was out with a group of fellow heroes in Sentinel-controlled territory. We know for sure that none of the others with her were mutants, and that makes a degree of sense; while the Sentinels would presumably have all kinds of sensors to scan with, their primary ones are specifically for mutant detection, plus there were telepathic Hounds trained to do the same. Heroes sent out on a scouting mission might want to minimise the chance of being spotted by leaving any mutants back at the more heavily shielded base.