After the observation of the strong near-threshold enhancement of proton-antiproton mass spectrum in J/ψ → γpp decay, lots of theoretical investigations have been available such as new resonance, the final-state pp interaction (FSI), pp bound state (or baryonium), glueball, or other exotic (tetra-quark) states. Here, we provide a short review on the current status, especially on the pertinent discussions concerning its relation to pp interaction, for which the emphasis is put on the recently constructed chiral potential.