  Measurements of the ratio of $B \to K^* \mu \mu $ to $B \to K^* e e $
branching fractions, $R_{K^*}$, by the LHCb collaboration strengthen the hints
from previous studies with pseudoscalar kaons, $R_K$, for the breakdown of
lepton universality, and therefore the Standard Model (SM), to $\sim 3.5
\sigma$. Complementarity between $R_K$ and $R_{K^*}$ allows to pin down the
Dirac structure of the new contributions to be predominantly SM-like chiral,
with possible admixture of chirality-flipped contributions of up to ${\cal{O}}(
\mbox{few} 10 \%)$. Scalar and vector leptoquark representations
$(S_3,V_1,V_3)$ plus possible ($\tilde S_2,V_2$) admixture can explain
$R_{K,K^*}$ via tree level exchange. Flavor models naturally predict leptoquark
masses not exceeding a few TeV, with couplings to third generation quarks at
$O(0.1)$, implying that this scenario can be directly tested at the LHC.
