Table 1. Biomarkers associated with BM in breast cancer.

Biomarkers		Prediction	Diagnosis	Prognostic	Predicting treatment efficacy	References
Proteins
	HR	√				[17,18]
	NTX		√	√	√	[21,22,23,25]
	CTX	√	√			[8,24,71]
	CAPG and GIPC1	√		√	√	[28]
	OPG		√			[33]
	RANKL		√			[33,34]
	BAP		√	√	√	[8,22,23,25,38]
	TRACP-5b		√	√	√	[23,38,40,41]
	ICTP		√		√	[38,71]
	DOCK4	√				[44,45]
	FGF23			√		[48]
	PTHrP(12-48)		√			[51]
Genes
	IL-1B	√				[52,72,73]
	MAF	√				[54]
	15-gene signature		√			[58]
	Kang's signature		√			[55,58]
	ZNF217	√				[61]
miRNAs
	miR-214-3p		√			[67]
	miR-218	√				[69]
	miR-126		√	√		[70]
	miR-206			√		[70]
	miR-335		√	√		[70]

BM = bone metastases; HR = hormone receptor; NTX = N-terminal cross-linked telopeptide of type I collagen; CTX = C-terminal cross-linked telopeptide of type I collagen; CAPG = macrophage-capping protein; GIPC1 = PDZ domain-containing protein GIPC1; OPG = osteoprotegerin; RANKL = receptor activator of nuclear factor κB ligand; BAP = bone alkaline phosphatase; TRACP-5b = tartrate-resistant acid phosphatase type 5b; ICTP = cross-linked carboxy-terminal telopeptide of type I collagen; DOCK4 = dedicator of cytokinesis 4; FGF23 = fibroblast growth factor 23; PTHrP = parathyroid hormone-related protein; IL-1B = interleukin-1B; MAF = musculo-aponeurotic fibrosarcoma oncogene homolog; ZNF217 = zinc finger protein 217; miRNA = microRNA.