The ICARUS-T600 detector, the first large-scale liquid Argon TPC, took data in the underground LNGS laboratory, detecting both CNGS beam and atmospheric neutrinos, proving the full maturity of the LAr-TPC technology. A sensitive search for $\nu_\mu \to \nu_e$ oscillations mediated by possible eV-scale sterile neutrinos, as observed by LSND, allowed to strongly constrain the corresponding parameter space. A dedicated short-baseline experiment (SBN) with three LAr-TPCs, where ICARUS-T600 will act as far detector, is in preparation at FNAL to will fully address this issue by searching for sterile neutrino oscillations, both in appearance and disappearance.