1. Bayer and Monsanto

In a rapidly consolidating sector already dominated by just a handful of players, Bayer AG’s $66 billion acquisition deal with U.S.-based Monsanto Co. has significant negative implications for farmers and the industry, experts say. The two companies, though, say the deal will be a boon to the agricultural industry — helping to feed an expanding population in a sustainable way — as well as farmers.

2. The $32 billion deal between Shire and Baxalta

Industry: ShirePharmacy.

After a lengthy six-month courtship, London-based drugmaker Shire announced plans to buy Baxalta in a $32 billion cash and stock offer.

3. The $30.6 billion bid for St Jude Medical by Abbott Laboratories

Industry: Medical Appliances and Equipment

In April 2016, Abbot Labs announced plans to buy St. Jude Medical for $25 billion in a cash and stock deal, and assume or refinance St. Jude’s net debt of about $5.7 billion.

4. The $28.1 billion acquisition of LinkedIn by Microsoft

Sector: Tech

Microsoft announced it would buy social networking company, LinkedIn for a smooth $26.2 billion in an all-cash deal. That took LinkedIn’s stock up 47% in trading. The deal, Microsoft’s’ largest ever by a $20 billion long shot, will “accelerate the growth of LinkedIn, as well as Microsoft Office 365 and Dynamics,” according to Microsoft CEO Satya Nadella.

5. The $16.6 billion deal for Tyco International by Johnson Controls

Sector: Auto Parts

Car parks manufacturer, Johnson Controls and Ireland-based security systems maker, Tyco International agreed to merge in a deal that would help Johnson Controls dodge the high, about 35%, corporate tax rate in the U.S. by moving headquarters to Ireland. The deal will lead to at least $500 million in savings in the first three years, and at least $150 million in annual tax savings, the companies said.

6. The $13.6 billion bid to buy Starwood by Marriott International

Sector: Service

Perhaps one of the most tense mergers and acquisitions of 2016 that ended with Starwood’s top bidder, Anbang Insurance, calling it quits, the acquisition of Starwood by Marriott International takes number four on the list. After several months of bidding, the two companies agreed to merge in March, becoming the world’s largest hotel chain in a cash and stock deal.

7. The $13.2 billion acquisition of Columbia Pipeline Group by TransCanada

Sector: Oil and Gas

The company behind the controversial Keystone XL oil pipeline, TransCanada, agreed to buy Columbia Pipeline Group for $10.2 billion in March, making the combined giant one of North America’s largest regulated natural gas transmission businesses in an all cash deal.

8. A $12.8 billion merger between IMS Health Holdings and Quintiles Transnational Holdings

Sector: Biotech

Contract medical research provider, Quintiles, agreed to merge with healthcare information company, IMS Health to make a giant known as Quintiles IMS in an all-stock deal.

9. The $12.4 billion acquisition of ADT by Protection

Sector: Security

A security service for residential and small business properties, ADT, agreed to be acquired by an affiliate of Apollo Global Management, and merged with another home security firm, Protection 1. The merger would give the combined company greater reach throughout the U.S. and Canada, and also help ADT accelerate its expansion into the commerical sector.

10. Great Plains Energy’s Bid for Westar Energy Worth $12.2 billion

Sector: Electrical Utilities

Great Plains Energy, based out of Kansas City, Mo., and Westar Energy, based out of Kansas, announced the deal late May in a cash and stock transaction. “The utility industry is facing rising customer expectations, increasing environmental standards and emerging cyber security threats. These factors, coupled with slower demand growth for electricity, are driving our costs and customer rates higher,” said Terry Bassham, chairman and chief executive officer of Great Plains Energy.