The relationship between missense mutation and cancer

in a tumor cell line, we isolate gene x that has a single missense mutation compared to WT gene. You isolate the WT of genex  and call it x-gene x . when we delete gene x from tumor cell this makes cell division slow, and cells stop growing independent of anchorage. When we delete both copies of x-gene x this causes cells to die. How can we test the relationship between missense mutation and cancer?

1. fuse x- gene x to gfp express it in normal cells and monitor its localization by flurences micro.

2. fuse x-gene x and gene x to gfp , express them in normal cells and compare their localizetion patterns

3. show that the missense mutation is suffiecent by introducing the indentical mutation into x-gene x expressing it in a noncancer cell line and monitoring cancer phenotypes

4. express the protien with the missense mutation purify it and show that it has biochemical activity in a test tube

5. show that the missense mutation is sufficient by converting the codon back to wild type expressing it in a non cancer line and monitoring cancer phenotypes.