RBP4 and liver cancer: As we know, SF, sTfR and CRP [23,24,25] can be used to judge the iron level, PA [26] can be used to judge the protein level, RBP4 [27] can be used to judge the VA level, ApoB [28] and D-D [29] can be used to reflect the risk of cardiovascular and cerebrovascular disease, AFP [30] is a marker of liver cancer development and progression, and CEA [31] is a preferred indicator of colon-cancer staging studies before surgical resection.