For your code

if(Dumper($page) =~ /===Comments===(.*?)=Microarray Data=/s) {  
            $lit_comments = $1; 
        }
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Search the match one time only

You want to do the stuff's repeated. You will use the while loop and use the 'g' (global modifier) in your code.

while(Dumper($page) =~ /===Comments===(.*?)=Microarray Data=/gs) {  
            $lit_comments = $1; 
        }
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Otherwise. Try this

Dumper($page) =~ s/===Comments===(.*?)=Microarray Data=/&my_process($&
+)/ges;

sub my_process
{
    my ($content)=@_;
    
    ## Do You stuff's Here

    return $content;
}
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