PNPLA3 and rheumatoid arthritis: &lt;i&gt;HLA DRB1*01&lt;/i&gt; and &lt;i&gt;*04&lt;/i&gt; Predisposition to Rheumatoid Arthritis and Polymorphisms of the &lt;i&gt;SLCO1B1&lt;/i&gt;, &lt;i&gt;MTHFR&lt;/i&gt; and &lt;i&gt;PNPLA3&lt;/i&gt; Genes Are Not Associated with Fatty Liver and Hepatotoxicity.