Researchers at Peking University have developed an innovative RNA codon expansion platform that incorporates pseudouridine-modified codons into mammalian messenger RNA, circumventing challenges of translational termination interference. This platform allows bioorthogonal, precise incorporation of noncanonical amino acids without disrupting native protein synthesis, representing a breakthrough in mammalian genetic code expansion and protein engineering. The approach could significantly advance synthetic biology and therapeutic protein design by expanding the functional repertoire beyond natural amino acids.