I have two tables, the start of each is given below:

Table 1: *All SNPs*

```
   SNp           Gene
rs1798922   ENSG00000167634
rs4677723   ENSG00000167634
rs1609823   ENSG00000104450
rs11597390  ENSG00000104643
rs7824557   ENSG00000104643
rs1371867   ENSG00000104450

```

Table 2: *Best SNP per gene*

```
  SNP            Gene
rs1371867   ENSG00000104450
rs7824557   ENSG00000104643
rs1671152   ENSG00000167634
rs11597390  ENSG00000095485
rs285757    ENSG00000185442

```

Table 1 shows a list of genes with their corresponding SNPs. As can be seen, the same gene is repeated in many places in the table. 

Table 2 is the result after filtering through all the SNPs for **each** gene in Table 1, and keeps only **one** SNP **per** gene (keeps best SNP according to the p-value, although that's not relevant here).

So in other words, there are some SNPs in Table 1 that's not included in Table 2, since Table 2 only keeps the best SNP for each gene. 

For **each** gene, I want to use R to compare the 2 tables and output back the SNPs that weren't included in Table 2 for that gene. So the specification for comparison is the Gene name, which will change constantly since there are many genes in the table.