Cardano has integrated with the Bitcoin ecosystem through BitcoinOS’s Grail Bridge, unlocking Bitcoin's liquidity for its DeFi ecosystem.Cardano becomes the first Layer 1 blockchain to use BitcoinOS infrastructure, tapping into Bitcoin's $1.3 trillion liquidity pool.The partnership aims to bridge the gap in the Bitcoin network by introducing infrastructure for DeFi activities.The integration enables trustless transfers of BTC and other Bitcoin-based assets on Cardano, and allows users to pay fees directly in Bitcoin.