  We present a study of the 1+1 flavor system of strongly interacting matter in
terms of the Polyakov$-$Nambu$-$Jona-Lasinio model. We find that though the
small isospin symmetry breaking brought in through unequal light quark masses
is too small to affect the thermodynamics of the system in general, it may have
significant effect in baryon-isospin correlations and have a measurable impact
in heavy-ion collision experiments.
