Sideways lipid presentation by the antigen-presenting molecule CD1c.

Summary: Imagine your immune system has tiny guard dogs (T-cells) that check ID cards (lipids) held by hands (CD1c molecules). Usually, the ID card fits perfectly in the hand. But scientists found that some ID cards are too bulky! Instead of dropping them, the hand holds two cards at once and lets the bulky part stick out the side. Because it sticks out the side, the guard dog can still read the hand without the bulky card getting in the way. Unfortunately, this can accidentally trigger the immune system to attack its own body.