  I discuss the implementation of the Peccei-Quinn mechanism in a minimal
realization of the Pati-Salam partial unification scheme. The axion mass is
shown to be related to the Pati-Salam breaking scale and it is predicted via a
two-loop renormalization group analysis to be in the window $m_a \in [10^{-11},
\, 3 \times 10^{-7}]$ eV, as a function of a sliding Left-Right symmetry
breaking scale. This parameter space will be fully covered by the late phases
of the axion Dark Matter experiments ABRACADABRA and CASPEr-Electric. A
Left-Right symmetry breaking scenario as low as 20 TeV is obtained for a
Pati-Salam breaking of the order of the reduced Planck mass.
