Growth factors mediate their diverse biologic responses (regulation of cellular proliferation. differentiation. migration and survival) by binding to and activating cell-surface receptors with intrinsic protein kinase activity named Receptor Tyrosine Kinases (RTKs). About 60 RTKs have been identified and can be classified into more than 16 different receptor families. https://www.remtavares.com/best-offer-Merrick-Backcountry-Grain-Free-Kitten-Pate-Canned-Wet-Cat-Food-5-5-oz-Cans-Case-of-24-p14288-limited-choice/