NPPB and hydrops fetalis: Though the aim of the research was the investigation of pathways associated with high lethality among patients with HF (these were the PI3K/Akt pathway, the MAPK pathway, the Ras signaling pathway, and epidermal growth factor receptor tyrosine kinase inhibitor resistance), the data from various layers (genetic, transcriptomic and proteomic) also highlighted some powerful disease markers (see in Table 2), among which are the abovementioned NT-proBNP and troponin T [54].