Additionally, Richter et al. assessed the plasma levels of the fractalkine ligand (CX3CL1) for the receptor, CX3CR1, in 349 patients with advanced systolic HF and found that CX3CL1 was a significant predictor of all-cause mortality with a hazard ratio for the third compared to the first tertile of 2.78 (31). Here, CX3CR1 is linked to hydrops fetalis.