  Let $n$ be an even number such that $n\equiv 0 \pmod{4}$. We show that a
power function $x^d$, with $d=2^{\frac{n+2}{2}}+2^{\frac{n-2}{2}}-1$, on
$\mathbb{F}_{2^n}$ is an APN function of degree $n/2$ which is CCZ-equivalent
to Kasami functions of degrees $n/2$ and $(n+4)/2$.
