STRING 9.05 
HCN1 [ENSP00000307342]
 
hyperpolarization activated cyclic nucleotide-gated potassium channel 1; Hyperpolarization-activated ion channel exhibiting weak selectivity for potassium over sodium ions. Contributes to the native pacemaker currents in heart (If) and in neurons (Ih). Activated by cAMP, and at 10-100 times higher concentrations, also by cGMP. May mediate responses to sour stimuli
HCN4 [ENSP00000261917]
 
hyperpolarization activated cyclic nucleotide-gated potassium channel 4; Hyperpolarization-activated ion channel with very slow activation and inactivation exhibiting weak selectivity for potassium over sodium ions. May contribute to the native pacemaker currents in heart (If) and in neurons (Ih). Activated by cAMP. May mediate responses to sour stimuli
Evidence suggesting a functional link:
Neighborhood in the Genome:  
none / insignificant.
    
Gene Fusions:  
none / insignificant.
    
Cooccurence Across Genomes:  
none / insignificant.
    
Co-Expression:  
none / insignificant.
    
Experimental/Biochemical Data:   yes (score 0.620).  
Association in Curated Databases:  
none / insignificant.
    
Co-Mentioned in PubMed Abstracts:   yes (score 0.790). In addition, putative homologs are mentioned together in other species (score 0.060).  
Combined Score:
 
0.635
 
Note: the two proteins have some sequence similarity (1191.3 bits over 871 amino acids. click here to see the alignment).
Evidence for specific actions:
Binding:yes (score: 0.620)