my @taxR = ("PLRV1", "PMTVS", "PVXHB");
my $curEntry = "PMTVS";
if($curEntry ~~ @taxR){
   print "do rest of stuff";
}

##</code><code>##

my @taxR = ("PLRV1", "PMTVS", "PVXHB");
my $curEntry = "PMTVS";
if( first { $_ eq $curEntry } @taxR ){
   print "do rest of stuff";
}