Why do cancer$-$causing mutations in tumor suppressor genes and oncogenes have different inheritance patterns?

An oncogene mutation creates a protein that promotes cell division. A single copy can trigger cell division, causing tumor formation.

Cancer$-$causing mutations permanently turn off oncogenes but only temporarily turn off tumor suppressor genes.

Cancer$-$causing mutations cause both copies of a tumor suppressor gene to become constitutively activated.

Tumor suppressor proteins are upstream in the cell cycle regulation pathway, whereas oncoproteins regulate more important control points downstream in the pathway.

The wild$-$type function of a tumor suppressor protein is to restrain cell division. A single functional copy will halt cell division and prevent tumor formation.