In the Universe of Marvel heroes can get their abilities in different ways, but apparently the actress who plays Black Widow may not be aware of this, since in an interview Scarlett Johansson said that Hulk was a mutant.
In the mythology of the so-called house of ideas there are the superhero mutants which obtained their powers by the x-gene, so that it is inherited, while there are other vigilante that gained their skills by an accident, as was the case with the giant scarlet.
This, although it might be a detail that for most it would be negligible, for many fans it is crucial, among one of the reasons is because you will be introduced to the X-Men in the MCU (Movie Universe of Marvel) in their following stages, so that any reference could be an important input for this.
That said, it was revealed in an interview to EW that the actress Scarlett Johansson said that Hulk was a mutantsomething that surprised several followers of the saga, however, it could be a mistake in the use of the term. In this talk the famous indicated that one of the moments more iconic for her in the MCU was when they met for the first time the Avengers.
“None of us knew if this movie (‘Avengers’) would work. It seemed like a crazy (because) there is a norse God, is the character of Tony Stark, and then there is a scientific mutant that has a problem of anger management,” explained the celebrity.
So unfortunately for fans of the X-Men, Hulk is not one of yours, although the key for his entry into the MCU would actually be Scarlet Witch, since she is in the comics if it is a mutant which in its new series ‘WandaVision’ I could talk about this topic.