Aliens: “We have the cure for cancer.”

Humans: “Great! What is it?”

Aliens: “Just stop your cells from reproducing. That creates translation errors which can result in run-away mitosis and mutation.”

Humans: “Uh… okay, but if we’re not using cells, what should we use to form our bodies instead?”

Aliens: “Sandstone is good. Marble is better.”

Humans: “Okay, we’ll give it a shot.”

3000 years of Egyptians and Greeks perfecting the sculpture later…

Humans: “Nope. Still got cancer.”