Woman have always been in search of the fountain of youth and the key to a wrinkle-free, eternally youthful glow.
One woman now says she has cracked the code by never cracking a smile.
In fact, she's remained stone-faced for 40 years and swears it's why her skin is so smooth.
The now 50-year-old nicknamed Mona Lisa has resisted the urge to grin and giggle since she was 10 years old - not at parties, not even at the birth of her daughter.
She says her poker face is why she doesn't have a single line of expression and some some experts believe it might actually work!
On the flip side, 70-year-old Christyne Remnant says she hasn't stopped smiling since she was 8 years old.
Remnant says that an ear-to-ear grin helps prevent wrinkles on her forehead.