One copy of Su(var)3-9311 strongly suppresses position effect variegation (PEV) at the w locus caused by In(1)wm4.
One copy of Su(var)3-9311 moderately suppresses the telomeric position effect (TPE) in stocks carrying a variegating P{hsp26-pt-T}39C-5 insertion at the telomere of the left arm of chromosome two.
The position effect variegation of the w gene seen in In(1)wm4 flies is completely suppressed by one copy of Su(var)3-9311.