Even though the LHC searches so far did not unveil the new physics particles, observations made at the LHC and at the B-factories point towards lepton flavor universality violation in both tree-level and loop-induced B-meson semileptonic decays. After a brief review of the status of these anomalies, I will discuss general implications that can be derived by using (i) an effective field theory approach and (ii) specific leptoquark models.