She’s her own twin
Taylor Muhl carries two sets of DNA—it’s akin to being two separate people. Muhl’s rare condition comes from her absorbing her fraternal twin in the womb. Known as chimerism, the phenomenon helps explain why Muhl is plagued by an autoimmune condition: She has two immune systems and two bloodstreams, and her body rejects her twin’s DNA as an invader. This has led to severe allergies her whole life; it also explains the unique birthmark that divides her abdomen at the midline, coloring the right side of her body. “I felt freedom [after the diagnosis] because for the first time in my life I knew why my stomach looks the way it does,” Muhl told People. Check out these fascinating facts about twins.