filtering R dataframe and show each variable once : <p>I have a huge dataframe that contains a column of gene's IDs. Each Gene ID appears in the column in a different number of times.
I want to extract from the dataframe a column that presents every Gene ID once, and at the same time I want to keep the data as a dataframe and not to change it to a list with factors.</p>

<p>example:
GeneID
589034
489034
589034
589034
48999
99449
99449</p>

<p>And i want my output to be:
GeneID
589034
489034
48999
99449</p>
