  Using the initial-state radiation method, the $e^+e^- \to K_S K_L$ cross
section from 1.98 to 2.54 GeV is measured in a data sample of 469 fb$^{-1}$
collected with the BABAR detector. The results are used in conjunction with
previous BABAR results for the $e^+e^- \to K^+ K^-$, $e^+e^- \to \pi^+\pi^-$,
$e^+e^- \to \pi^+\pi^-\eta$, and $e^+e^- \to \omega\pi\pi$ cross sections to
investigate the nature of the resonance structure recently observed by the
BESIII experiment in the $e^+e^- \to K^+ K^-$ cross section.
