They didn't "add art" because they are comic book artists. STEAM is a common variation. Why? STE(A)M is about creative problem solving. The skills that are proving critical in 21st Century teaching and learning - the skills that are helping people be successful in science, technology, engineering and math, are skills native to arts education. The 'A' isn't included because it's a comic book. The 'A' is included because these five disciplines all grow from one body of skills.

STEAM is commonly used - though not as common as STEM - and it's important to know that it's not an add-on. Arts education can have a powerful, life-long impact on students, most of whom will not become artists. But we're not teaching them to be artists. We're teaching them to become stronger people.