Knudson: Two Hit Hypothesis

                                                           Evolution Of Cancer 

                                                         
                                                                Boveri (1904)

                Cancer predisposition through chromosomal inheritance/oncogenes


                                                       Cancer and Genetics 

                                          Knudson (1971):  " Two Hit " Hypothesis 

Knudson (1971) used Retinoblastoma as a model for explaining Tumorigenesis 

Cell can initiate a tumor only when it contains TWO Mutant Alleles

Person who inherits a mutant allele must experience a Second Somatic Mutation

Second Somatic Mutation: Tumorigenesis

Hereditary Tumour: (Inherited  Mutation + Acquired Mutation)

Sporadic Tumour ( 2 Acquired Mutations)

Eg: p53 Tumor Suppressor Gene 

Mutated p53

Knudson: The Observer 

Cancer (Snapshot)

Germline+Acquired Mutation (Carcinogen): Increases the risk of Cancer 

: