Turan's conjecture on graph-property sensitivity

Let $f$ be a non-trivial graph property for graphs with $n$ vertices, so that $f$ is a Boolean function of the ${n \choose 2}$ possible edges. Turan's conjecture. The sensitivity satisfies

$$s(f)\geq n-1.$$

Turan had previously proved the lower bound $s(f)\geq \lfloor n/4\rfloor$; the conjecture remains unresolved more than thirty years after it was formulated.