Hadronic Light-by-Light Contribution to Muon g-2

I present the main results obtained in a recent work together with Eduardo de Rafael and Arkady Vainshtein on the hadronic light-by-light contribution to muon g-2. We came to the estimate a^{HLbL}_\mu = (10.5 +- 2.6) x 10^{-10}. Here, some emphasis is put in pointing out where the future KLOE2 two-photon experimental program can help to reduce the present model dependence of a^{HLbL}_\mu.