Table 1.

Somatic mutation of PIK3CA in breast cancer cell lines and primary tumors

Exon	Nucleotide	Amino acid	Functional domain	Cell lines	Tumors	Total
9	C1616G	P539R	Helical	1 (BT20)	1
9	G1624A	E542K	Helical		3	3
9	G1633A	E545K	Helical	2 (MDA361, MCF7)	8	10
9	A1634G	E545G	Helical		1	1
20	A3140G	H1047R	Kinase	2 (BT20, UACC893)	5	5
20	A3140T	H1047L	Kinase		1
No. with mutations				5	19	22
No. samples screened				15	92
Percent of cases with mutations				33.3	20.6