[Breaking News] The development of Bitcoin Layer 2 may usher in a major breakthrough. An important proposal, the reintroduction of the OP_CAT opcode, is expected to pave the way for the maturity of Bitcoin's L2 solution. OP_CAT, or "Operation Concatenate", is an opcode in the Bitcoin script language that allows two data elements to be concatenated. Although it was disabled due to security issues in 2010, the 2021 Taproot upgrade has addressed these concerns. The restart of OP_CAT will enhance Bitcoin script capabilities and enable more complex transaction functions. In addition, OP_CAT is crucial to advancing Bitcoin's L2 solution because it enhances the scripting capabilities required for more complex and trustless Bitcoin infrastructure. Currently, the Bitcoin community is discussing the reactivation of OP_CAT, and if the proposal is approved, it is expected to be implemented within six months to a year.