  The chiral magnetic effect (CME) is an exact statement that connects via the
axial anomaly the electric current in a system consisting of interacting
fermions and gauge field with chirality imbalance that is put into a strong
external magnetic field. Experimental search of the magnetically induced
current in QCD in heavy ion collisions above a pseudocritical temperature
hints, though not yet conclusive, that the induced current is either small or
vanishing. This would imply that the chirality imbalance in QCD above $T_c$
that could be generated via topological fluctuations is at most very small.
Here we present the most general reason for absence (smallness) of the
chirality imbalance in QCD above Tc. It was recently found on the lattice that
QCD above Tc is approximately chiral spin (CS) symmetric with the symmetry
breaking at the level of a few percent. The CS transformations mix the right-
and left-handed components of quarks. Then an exact CS symmetry would require
absence of any chirality imbalance. Consequently an approximate CS symmetry
admits at most a very small chirality imbalance in QCD above Tc. Hence the
absence or smallness of an magnetically induced current observed in heavy ion
collisions could be considered as experimental evidence for emergence of the CS
symmetry above Tc.
