library_construction_protocol: Ultraviolet-crosslinked (400 mJ/cm²) RAW264.7 macrophages (4 × 10^7) were lysed in lysis buffer and sonicated. Lysates were treated with RNase I to fragment RNA and DNase I to remove DNA. Linearized DNA was amplified with Phusion High-Fidelity polymerase (12–15 cycles) using indexed primers. Final libraries were size-selected (175–350 bp) on a 3% TBE gel, quantified (Qubit), and validated via Bioanalyzer.