  The effect of the isospin/charge asymmetry and an external magnetic field in
the location of the critical end point (CEP) in the QCD phase diagram is
investigated. By using the 2+1 flavor Nambu--Jona-Lasinio model with Polyakov
loop (PNJL), it is shown that the isospin asymmetry shifts the CEP to larger
baryonic chemical potentials and smaller temperatures, and in the presence of a
large enough isospin asymmetry the CEP disappears. Nevertheless, a sufficiently
high external magnetic field can drive the system into a first order phase
transition again.
