В третьих, не наблюдалось известных активирующих мутаций гена рецептора эпидермального фактора роста (epidermal growth factor receptor, EGFR) и транслокаций гена киназы анапластической лимфомы (anaplastic lymphoma kinase, ALK).

There are two types of mutation.
Activating mutation causes the gene to be expressed at the wrong time at the wrong level or even with a new function. So this means that activating in oncogenes are tumorigenic.
Their converse are inactivating mutations, and these cause reduced function of a gene. So either less RNA, or protein is made. The inactivating mutations in tumor suppressors are tumorigenic.