ag.algebraic geometry - Vanishing of Self-Ext groups of vector bundles

Let $E$ be a rank two vector bundle on $mathbb{P}^n$. Assume that $text{Ext}^1(E, E)=0$. Will $text{Ext}^2(E, E)$ be zero? Why? Any geometric explanation (in terms of deformation theory?)?

Edit: As pointing out by Angelo, in the case $n=2$, the answer is no. However, I really want to know when $ngeq 4$.