What are the different PI3K isoforms?

Class I PI3Ks include four catalytic isoforms: PI3Kα (PIK3CA) PI3Kβ (PIK3CB) PI3Kδ (PIK3CD) PI3Kγ (PIK3CG) PI3Kα and β are broadly expressed, while PI3Kδ and γ are enriched in leukocytes and play critical roles in immune regulation. Isoform selectivity is an important consideration in drug development due to toxicity and immune effects.