Code for the side of a paired organ, or the side of the body on which the reportable tumor originated. This applies to the primary site only.

0	Not a paired site
1	Right: origin of primary
2	Left: origin of primary
3	Only one side involved, right or left origin unspecified
4	Bilateral involvement at time of diagnosis, lateral origin unknown for a single primary; or both ovaries involved simultaneously, single histology; bilateral retinoblastomas; bilateral Wilms' tumors
5	Paired site: midline tumor
9	Paired site, but no information concerning laterality