This project aims to identify and quantify TPM3P9 RNA-associated proteins in primary breast cancer cells (PBCs#2/#3/#5) and bone-metastatic breast cancer cells (BMBCs#2/#3/#5) using 4D-DIA LC–MS/MS. RNA pulldown assays were performed with tRSA-based TPM3P9 RNA to capture interacting proteins, which were subsequently analyzed by 4D-DIA-based quantitative proteomics. The objective is to elucidate the translational regulation mechanism of osteolysin in bone-metastatic breast cancer cells and to identify specific RNA-binding proteins involved in osteolysin translation.