Humans, also known as Homo Sapiens, were a species living on the planet Earth. Unlike the stage that advanced them, mutants, humans did not possess extraordinary powers through the X-Gene. They were also more prone to death.
Mutant or Not? Edit
Given that mutants were simply the next stage of human evolution, the Sentinels realized that mutants would eventually "become" humans by becoming the normal. Hence, as there was no true inherent difference between humans and mutants, simply the acquisition of one gene, humans too became a part of the Sentinel bloodshed in 2023.