  We suggest a few particle physics processes in which excited 2p pionium
$\mathrm{A}^\prime_{2\pi}$ may be observed. They include the
$e^+e^-\to\pi^+\pi^-$ annihilation, the $V^0\to\pi^0\ell^+\ell^-$ and
$K^\pm\to\pi^\pm\ell^+\ell^-$ ($\ell=e,\mu$) decays, and the photoproduction of
two neutral pions from nucleons. We analyze available experimental data and
find that they, in some cases, indicate the presence of 2p pionium, but do not
provide definite proof.
