They had been banished from their tribe for murder. According to Anishinaabe oral tradition, these five Sac were killed by local Dakota in the late 18th century.Place names with "Sauk" references include: 

Iowa: Sac City, Sac County, and Sac Township. Illinois: Sauk Village; Sauk Valley: the cities of Dixon, Sterling, Rock Falls and the surrounding area; Sauk Trail, a winding road south of Chicago, said to follow an old Indian trail; Johnson-Sauk Trail State Recreation Area; and Black Hawk College [Moline and Kewanee, IL]. Michigan: The name of Saginaw is believed to mean "where the Sauk were" in Ojibwe; and the Saginaw Trail is said to follow an ancient Native American trail. US Route 12 in Michigan is said to follow the Sauk Native American trail. Minnesota: City of Sauk Centre, Le Sauk and Little Sauk townships, Lake Osakis, Sauk River, Sauk Rapids.
Epidemiology
Retinoblastoma presents with cumulative lifetime incidence rate of one case of retinoblastoma per 18000 to 30000 live births worldwide. A higher incidence is noted in developing countries, which has been attributed to lower socioeconomic status and the presence of human papilloma virus sequences in the retinoblastoma tissue.Almost 80% of children with retinoblastoma are diagnosed before three years of age and diagnosis in children above six years of age is extremely rare. In the UK, bilateral cases usually present within 14 to 16 months, while diagnosis of unilateral cases peaks between 24 and 30 months. See also
Eye cancer
Eye examination
Retinoblastoma protein

References
External links
Retinoblastoma information from MedlinePlus
retinoblastoma at NIH/UW GeneTests
RB1 Mutation Database
Retinoblastoma at Curlie
NCBI Genetic Testing Registry