In MCF-10A cells, other cancer-associated modes of PI3K pathway activation, namely expression of the helical E545K mutant of PIK3CA, the D560Y mutant of PIK3R1 (the p85 regulatory subunit of PIK3CA) as well as overexpression of PIK3CAWT (reflecting PIK3CA amplification in cancer), all displayed more centrosomes than parental cells (Supplementary Fig. 6d). The gene discussed is PIK3R1; the disease is cancer.