PIK3CD and Arthritis: Due to their crucial involvement in various physiological functions, it is not surprising that class I PI3K inhibitors are implicated in the treatment of a range of diseases such as arthritis [22], thrombosis, asthma [23], inflammation, cardiovascular diseases, PIK3CA-related overgrowth syndromes, etc. Nevertheless, class I PI3K inhibitors are above all well-recognised as potential anticancer agents.