The phrase "activity is not required" is correct and usable in written English.
It can be used to indicate that participation in a specific activity is optional or not mandatory.
Example: "For this workshop, attendance is encouraged, but participation in the group activity is not required."
Alternatives: "participation is optional" or "involvement is not necessary."
It is likely that due to prior induced Col2a1-driven recombination, constant Col2a1 activity is not required to activate the Tet-on system in our transgenic mouse.
These results support the idea that Zap70 catalytic activity is not required for integrin activation in CTL.
These results suggest that calcineurin activity is not required for the dephosphorylation and activation of TFEB, and that a different, Ca2+-independent phosphatase(s) may possibly dephosphorylate TFEB and facilitate its nuclear translocation under these conditions.
As Cdk1 activity is not required for Cdc5 to be active [5] we considered other potential mechanisms as to how Cdk1 regulates elimination of Swe1.
Under this condition, heparanase activity was fully inhibited, further emphasizing that heparanase enzymatic activity is not required for its inhibition of lymphocyte activation.
As expected, we found that prior treatment with the Chk1 inhibitor results in inhibition of BAK multimerization with the Y108A mutant further in line with the findings that Chk1 activity is not required for the initial step of BAK activation.
GRed activity is not required for the selenite-dependent synthesis of GPx.
This activity is not required for the nuclear localization of p48v-myb.
We found that matrix metalloproteinase activity is not required for matrix alignment before cell migration.
Rad52 ssDNA annealing activity is believed to mediate second-end capture during synthesis-dependent strand annealing (SDSA) in yeast30, but such activity is not required in mammalian cells, since HR is not significantly altered in Rad52-deficient cells.
If life emerged on Earth without plate tectonics, then that would imply tectonic activity is not required for life.
