The phrase "a functional link between these two" is correct and usable in written English.
You can use it when discussing a relationship or connection between two entities, concepts, or items, particularly in academic or analytical contexts.
Example: "The study aims to establish a functional link between these two variables to better understand their interaction."
Alternatives: "a practical connection between these two" or "an operational relationship between these two".
Our findings might suggest a functional link between these two functions of the reticular system, i.e. maintenance of muscle tone and stabilization of motor control, and the regulation of arousal.
Although our results suggest that Wnt4 and Jnk2 have similar functions in BM LSK maintenance, we wanted to confirm a functional link between these two molecules in vivo.
Cav-1 and IGF-IR play independent roles in the regulation of cell growth, adhesion and migration but a functional link between these two proteins has been demonstrated [19], [32].
This concurrent effect on memory consolidation and post-training dephospho-eEF-2 strongly suggested a functional link between these two events, because the blockade of NMDA receptors was able to block both of them.
The use of MK-801 then revealed that both post-training dephospho-eEF-2 and memory consolidation were neuronal activity-dependent, and that there was a functional link between these two events.
TSC2 is required for the normal trafficking of PC-1 from the Golgi to the membrane [23] and more recently, PC-1 was also shown to interact with TSC2 [22], establishing a functional link between these two proteins.
Thus, the similarity in the ligand-binding sites helps establish a functional link between the two proteins.
In vivo modification of triadin expression results in modification of Cav-3, indicating a functional link between the two proteins.
The interaction of both BRCA1 and BRCA2 with RAD51 suggests a functional link between the three proteins in the RAD51-mediated DNA damage repair process.
A negative correlation between lipids and glutamine was found, suggesting a functional link between these molecules.
However, a functional link between these neurons and the avian photoperiodic response was elusive.
