  The observation of X-ray lines in the afterglow of GRB 011211 has been
reported, and challenged. The lines were interpreted as blue-shifted X-rays
characteristic of a set of photoionized ``metals'', located in a section of a
supernova shell illuminated by a GRB emitted a couple of days after the
supernova explosion. We show that the most prominent reported lines coincide
with the ones predicted in the ``cannonball'' model of GRBs. In this model, the
putative signatures are Hydrogen lines, boosted by the (highly relativistic)
motion of the cannonballs (CBs). The corresponding Doppler boost can be
extracted from the fit to the observed I-, R- and V-band light-curves of the
optical afterglow of GRB 011211, so that, since the redshift is also known, the
line energies are --in the CB model-- predicted. We also discuss other GRBs of
known redshift which show spectral features generally interpreted as Fe lines,
or Fe recombination edges. The ensemble of results is very encouraging from the
CB-model's point of view, but the data on each individual GRB are not good
enough to draw (any) objectively decisive conclusions. We outline a strategy
for X-ray observers to search for lines which, in the CB model, move
predictably from higher to lower energies.
