Hepatocellular carcinoma is the most frequent form of liver cancer. In a patient with heritable hepatocellular carcinoma, formation of the tumor was associated with eight genetic alterations affecting two different oncogenes and three different tumor-suppressor genes. These alterations are: i. mitotic recombination ii. a deletion of a chromosomal region iii. trisomy iv. a duplication of a chromosomal region v. uniparental disomy vi. a point mutation vii. another point mutation viii. yet another point mutation For parts (a)-(b) below, supply all possible correct answers from the preceding list. Remember that the majority of point mutations are loss-of-function mutations. a. Which of the mutations from the preceding list is likely to affect a proto-oncogene?