IBSP and prostate cancer: Furthermore, we identified a homeobox B13 (HOXB13) transcription factor as an upstream regulator of HOXA11-AS. In cooperation with HOXB13, HOXA11-AS regulated the expression of chemokines, integrins, and related genes (e.g., integrin-binding sialoprotein (IBSP)) to promote the bone-specific metastasis of prostate cancer.