C#: Confusion about ToUpper() and ToLower()

if I do something like this...

String myVar = "in";
if(myVar.ToUpper() == "in")
{
    //do something
}

This is not going to go inside "if" block ..right?

or

Is it going to check BOTH for "in" AND "IN" and do whatever is there inside that if? If so, why is that ? Isn't it supposed to skip what's inside of "if" block?

Same confusion is about ToLower() too

Edit: So to check for both cases, I need to write:

if((myVar.ToUpper().Equals("in"))&&(myVar.Equals("in")))

Like this..right?